NASDAQ: CATC Parent of Cambridge Trust Company Investor Presentation January 24, 2023 Exhibit 99.1

03 Company Profile 07 Financial Highlights 20 Strategic Focus 26 Appendix Contents This presentation includes non-GAAP measures and should be reviewed with the Company’s Q4 2022 Earnings Release and SEC filings.

Company Profile Banking subsidiary: Cambridge Trust Company (1890) Private Bank & Wealth Management Firm Headquarters: Harvard Square, Cambridge, MA Client Wealth Assets: $4.1 billion Banking Assets: $5.6 billion Gross Loans: $4.1 billion Total Deposits: $4.8 billion Noninterest income: 23% of revenue NASDAQ: CATC Market Cap: $664 million* As of December 31, 2022 *Market Cap is as of January 12, 2023.

Why Cambridge Bancorp? Market of operations offer significant long term growth prospects Private Banking business model with diversified fee revenue through wealth management focus Strong financial performance with excellent asset quality track record Low cost core deposit base Financially and strategically attractive acquisitions Client

Geographic Footprint Source: S&P Global Market Intelligence; FDIC 1 2 3 North Andover Andover Concord Winchester Cambridge Portsmouth Boston Concord Manchester Bedford Dover North Hampton Stratham Lexington Weston Wellesley Needham CATC Branches (22) CATC Wealth Offices (5) Newton

Market Characteristics 1: Source: S&P Global Market Intelligence as of 2022, and Bureau of Labor Statistics as of November and December 2022. 2: Source: Newmark Boston Office Market and Life Science Reports Q3 2022, Boston Business Journal April 2021. Unemployment Rates1 Median Household Income ($000s)1 Proj. Household Income Change (’23 – ’28)1 Wealth Management capability is well-suited to the highly affluent Boston and southern New Hampshire markets Greater Boston economy is diversified; the region is a global hub for innovation, healthcare, life sciences, and education2 Greater Boston lab market remains healthy, and in previous recessions, the biotech sector has outperformed the market2 Cambridge Trust’s private banking model caters to entrepreneurial local communities Cambridge Lab Space Vacancy2

Strong Financial Performance Operating Net Income and Operating Diluted Earnings Per Share 5-Year EPS CAGR (through 2022) +11.3% In dollars *Operating Net Income and Operating Diluted EPS are adjusted to exclude merger related and other non operating items. Dollars in millions

2022 Performance Highlights Operating EPS $7.80 Operating ROAA 1.10% Operating ROTCE 14.18% $56.5MM Operating Net Income 57.99% Operating Efficiency Ratio 13.3% Organic Loan Growth 0.00% Net Recoveries / Total Loans (Annualized) 0.12% NPAs to Total Assets 8.12% Tangible Common Equity Ratio

Q4 2022 Performance Highlights 1: Adjusted net interest margin excludes the impact of merger related loan accretion. Operating EPS $1.92 Operating ROAA 1.08% Operating ROTCE 13.61% $15.0MM Operating Net Income 3.01% Adjusted Net Interest Margin1 57.32% Operating Efficiency Ratio 3.6% Quarterly Organic Loan Growth 0.93% Allowance for Credit Loss Ratio $57.15 Tangible Book Value per Share

Strong Capital Position & Liquidity Capital Position* Tangible Book Value per Share Total access to funds of $1.5B *Current quarter capital ratios are estimated. Tangible Common Equity is not a regulatory capital ratio. **Minimum Capital Required For Capital Adequacy Plus Capital Conservation Buffer. Tangible Common Equity and Tangible Book Value Per Share are non-GAAP measures. As of December 31, 2022 Liquidity ($MM) 5 - Year CAGR (through 2022) +11%

Wealth Management & Noninterest Income Client Wealth Assets ($MM) Wealth Management Revenue ($MM) Net Client Flows ($MM) Noninterest Income ($MM) 2018 2019 2020 2021 2022 Starting AUM $2,971 $2,760 $3,287 $3,994 $4,656 Acquired AUM* 339 Net Flows (176) (5) (69) 90 (218) Net Market Impact (35) 532 437 572 (562) Ending AUM $2,760 $3,287 $3,994 $4,656 $3,876 Custody Assets 117 165 174 197 184 Total WM Assets $2,877 $3,453 $4,168 $4,853 $4,060 *Acquired in our merger with Wellesley Bancorp, Inc. AUM is comprised of approximately 58% equities, 28% fixed income, and 14% cash/other as of December 31, 2022. AUM Fee represents the weighted average fee on Assets Under Management during the period. Listed as the 18th Largest Independent Investment Advisers in Massachusetts by the Boston Business Journal in 2022 NII was 23% of Revenue in 2022

Total Assets and Loans Total Assets ($MM) Total Loans ($MM) Loan Portfolio 5 - Year Loans CAGR (through 2022) +25% 2019, 2020 and 2022 include acquired balances from Optima Bank & Trust Company, Wellesley Bancorp, Inc., and Northmark Bank, respectively. $4.1B outstanding as of December 31, 2022 55.7% Commercial 44.3% Consumer 4.26% Q4 2022 average yield excluding fair value accretion As of December 31, 2022

Deposit and Net Interest Margin Profile Total Deposits ($MM) Non-Interest-Bearing Deposits ($MM) Deposit Composition 5 -Year CAGR (through 2022) +21% Q4 2022 Avg. Cost of Deposits1: 0.45% December 31, 2022 Spot Cost of Deposits1: 0.80% Core Deposits 88% 2019, 2020 and 2022 include acquired balances from Optima Bank & Trust Company, Wellesley Bancorp, Inc., and Northmark Bank, respectively. 1: Adjusted net interest margin excludes the impact of merger related loan accretion and PPP income. Cost of Deposits excludes wholesale deposits. 1 1

Commercial Banking *Commercial & Industrial excludes PPP loans for years 2020 & 2021. Business Deposits represented 52% of core deposits Focused on continued diversification of the commercial portfolio into Commercial & Industrial Dedicated and centralized credit risk management function As of December 31, 2022 Commercial Loans ($MM)

By Sector Commercial Real Estate Loan Portfolio 5 By Geography Portfolio Details: $1.9 billion outstanding as of December 31, 2022 $1.7 million average loan size

By Industry Industry breakout excludes PPP loans Commercial & Industrial Loan Portfolio By Geography Portfolio Details: $351 million outstanding as of December 31, 2022 $577,000 average loan size

Consumer Loan Portfolio $1.8B outstanding as of December 31, 2022 Weighted Average FICO 785** *The Weighted Average LTV calculation only includes one collateral property value for loans with multiple collateral and excludes loans with a zero balance. **Most Recent Weighted Average FICO Score, excluding loans with a zero balance. As of December 31, 2022

Asset Quality Highlights NPLs / Loans Reserves / Loans (1) Annualized Net Charge Offs (Recoveries)/Loans NPAs / Assets 14-year average NCOs of 0.01% 1: The Company adopted CECL in Q1 2020. As a result of the COVID-19 pandemic, the Company increased the allowance for credit losses in 2020. The Reserve to Loan level in 2020 and 2021 excludes PPP loans.

Allowance for Credit Losses (ACL) Allowance for Credit Losses: Dollars in millions ACL Key Attributes: Sophisticated model uses loan level probability of default loss given default discounted cash-flows as the primary basis for the quantitative loss estimation Ending Unemployment Rate in forecast period: 4.23% Forecast Period: 2 Quarters Reversion Period: 4 Quarters Commercial Loans ACL Ratio Q4: 1.03% Consumer Loans ACL Ratio Q4: 0.81% 1.05% 0.96% 0.93%

Strategic Focus

Strategic Progress and Focus Completed merger with Northmark Bank adding attractive clients and markets Committed $140 million to support affordable housing in Massachusetts and New Hampshire by partnering with the Massachusetts Housing Partnership and New Hampshire Housing Supported clients & communities during the pandemic which included $293M in PPP Lending Named the 18th Largest Independent Investment Advisers in Massachusetts (according to Boston Business Journal) Named as one of the region’s top corporate charitable contributors (according to Boston Business Journal) Increased resources to support expansion of business development initiatives Leverage private banking model in highly attractive markets Increase brand awareness Expand Wealth Management assets under management Expand client base & deepen existing relationships to grow deposit base Grow and diversify Commercial Banking opportunities & relationships Recent Progress Strategic Focus

“At Cambridge Trust, corporate responsibility isn’t just core to our values as a company, it’s the way we’ve done business for more than 130 years.” -Denis Sheahan, President and CEO Your Bank Our People Our Communities We foster an ingrained focus on employee engagement, diversity, equity and inclusion (DE&I), and career development that allows our people to achieve their full potential. We only succeed if we serve as a true financial partner to the communities in which we work and live.    We have an obligation to reduce our environmental impact and empower our people, communities, and customers. $140 Million Voluntary loan commitment to the Massachusetts Housing Partnership and New Hampshire Housing supporting affordable housing and economic development $113 Million Solar lending and hydropower for commercial customers across New England 56% With nine women on our Board of Directors at Cambridge Bancorp, one of the highest number of women for companies listed on the NASDAQ.* Corporate Responsibility at Cambridge Trust *Source: S&P Global Market Intelligence © 2022. Additional information can be found within the corporate responsibility section of our website Charitable Giving Donated to over 280 organizations supporting our local communities in 2022 23% Of all employees are racially or ethnically diverse, which includes 11% of those who are Vice Presidents and above Consumption We are making investments in technology to reduce the use of paper and carbon emissions

2023 Financial Expectations Loans (end of period) Core Deposits (end of period) Adjusted Net Interest Margin1 Non-Interest Income Allowance for Credit Loss Effective Tax Rate Capital Growth range of 0% - 5% Growth range of 2% - 5% Full Year: 2.85% - 3.00% Reduction between 0% - 5% No BOLI policy gain in 2023 Full year impact of lower AUM balances Maintain excellent credit quality Ratio 0.90% - 1.00% 26% - 27% Maintain strong capital levels Operating Non-Interest Expense Growth range of 0% - 3% Includes full year impact of Northmark Bank merger Full year 2022 operating expense of $107.3 million 2023 Financial Expectations assume that Fed Funds reaches 5% in Q1 2023 and remains at 5% for 2023. 1: Adjusted net interest margin excludes the impact of merger related loan accretion and PPP income.

Stock Price Performance and Dividend Trend Source: S&P Global Market Intelligence © 2022 as of December 31, 2022. 2022 Dividends includes all dividends declared through December 31,2022. 23 years of increased dividends (1999 – 2022) Stock Price Performance 8%

Why Cambridge Bancorp? Focused private banking business model Attractive geographic markets Affluent client base Expanding commercial services Investing for future growth Consistently profitable Strong returns Core deposit funded Well-capitalized Strong asset quality Sound underwriting acumen and risk management practices Client-centric service culture Loyal client base Experienced, conservative leadership Commitment to our community Business Model Performance Credit Culture

Appendix

Appendix: Organic Loan and Deposit Growth Table Balance Acquired relates to the merger with Northmark Bank which was completed on October 1, 2022. December   31 , 2022 December   31 , 2021 Balance Acquired Organic Growth/(Decline) $ Organic Growth/(Decline) % Loans Residential mortgage 1,648,838 $ 1,415,079 $ 114,775 $ 118,984 $ 8.4% Commercial mortgage 1,914,423 1,511,002 155,848 247,573 16.4% Home equity 111,351 87,960 15,466 7,925 9.0% Commercial & Industrial 350,650 269,446 16,122 65,082 24.2% Consumer 37,594 35,619 1,004 971 2.7% Total loans 4,062,856 $ 3,319,106 $ 303,215 $ 440,535 $ 13.3% Deposits Demand 1,366,395 $ 1,393,935 $ 137,651 $ (165,191) $ (11.9%) Interest bearing checking 908,961 763,188 17,831 127,942 16.8% Money market 1,162,773 1,104,238 67,942 (9,407) (0.9%) Savings 790,628 907,722 53,002 (170,096) -18.7% Core deposits 4,228,757 4,169,083 276,426 (216,752) (5.2%) Certificates of deposit 205,060 159,367 96,703 (51,010) (32.0%) Wholesale Certificates of Deposits 381,559 2,702 - 378,857 14,023.6% Total Certificate of Deposits 586,619 162,069 96,703 327,847 202.3% Total deposits 4,815,376 $ 4,331,152 $ 373,129 $ 111,095 $ 2.6% December 2022 vs December 2021

Net Interest Income (NII) Sensitivity As of December 31, 2022 Appendix: Interest Rate Risk Profile These estimates of changes in the Company’s net interest income require us to make certain assumptions including loan- and mortgage-related investment prepayment speeds, reinvestment rates, and deposit maturities and decay rates. These assumptions are inherently uncertain and, as a result, we cannot precisely predict the impact of changes in interest rates on net interest income. Although our analysis provides an indication of our interest rate risk exposure at a particular point in time, such estimates are not intended to, and do not, provide a precise forecast of the effect of changes in market interest rates and will differ from actual results.

Forward Looking Statements and Non-GAAP Measures Certain statements herein may constitute “forward-looking statements” as defined in the Private Securities Litigation Reform Act of 1995. Such forward-looking statements about the Company and its industry involve substantial risks and uncertainties. Statements other than statements of current or historical fact, including statements regarding the Company’s future financial condition, results of operations, business plans, liquidity, cash flows, projected costs, the impact of any laws or regulations applicable to the Company, and measures being taken in response to the COVID-19 pandemic and the impact of the COVID-19 pandemic on the Company’s business are forward-looking statements. Words such as “anticipates,” “believes,” “estimates,” “expects,” “forecasts,” “intends,” “plans,” “projects,” “may,” “will,” “should,” and other similar expressions are intended to identify these forward-looking statements. Such statements are subject to factors that could cause actual results to differ materially from anticipated results. Such factors include, but are not limited to, the following: the businesses of Cambridge and Northmark may not be combined successfully, or such combination may take longer to accomplish than expected; the cost savings from the merger may not be fully realized or may take longer to realize than expected; operating costs, customer loss and business disruption following the merger, including adverse effects on relationships with employees, may be greater than expected; changes to interest rates; the ability to control costs and expenses; the current global economic uncertainty and economic conditions being less favorable than expected; disruptions to the credit and financial markets; changes in the Company’s accounting policies or in accounting standards; weakness in the real estate market; legislative, regulatory, or accounting changes that adversely affect the Company’s business and/or competitive position; the Dodd-Frank Act’s consumer protection regulations; the duration and scope of the COVID-19 pandemic and its impact on levels of consumer confidence; actions that governments, businesses and individuals take in response to the COVID-19 pandemic; the impact of the COVID-19 pandemic and actions taken in response to the pandemic on global and regional economies and economic activity; a prolonged resurgence in the severity of the COVID-19 pandemic due to variants and mutations of the virus; the pace of recovery when the COVID-19 pandemic subsides; disruptions in the Company’s ability to access the capital markets; and other factors that are described in the Company’s filings with the Securities and Exchange Commission, including the Annual Report on Form 10-K for the year end December 31, 2021, which the Company filed on March 14, 2022. The Company does not undertake, and specifically disclaims any obligation, to publicly release the result of any revisions which may be made to any forward-looking statements to reflect the occurrence of anticipated or unanticipated events or circumstances after the date of such statements. You are cautioned not to place undue reliance on these forward-looking statements. This presentation contains financial information determined by methods other than in accordance with accounting principles generally accepted in the United States of America (“GAAP”). This information includes operating net income and operating diluted earnings per share, tangible book value per share and the tangible common equity ratio, operating return on average assets, operating return on tangible common equity, and operating efficiency ratio.   Operating net income and operating diluted earnings per share exclude items that management believes are unrelated to its core banking business such as merger and acquisition expenses, gain (loss) on disposition of investment securities, and other items. The Company’s management uses operating net income and operating diluted earnings per share to measure the strength of the Company’s core banking business and to identify trends that may to some extent be obscured by such excluded gains or losses. Management also supplements its evaluation of financial performance with an analysis of tangible book value per share (which is computed by dividing shareholders’ equity less goodwill and acquisition related intangible assets, or “tangible common equity,” by common shares outstanding), the tangible common equity ratio (which is computed by dividing tangible common equity by tangible assets, defined as total assets less goodwill and acquisition related intangibles), return on average assets and return on tangible common equity on an operating basis, and the operating efficiency ratio (which is computed by dividing noninterest expense adjusted for non-operating expenses and total revenue adjusted for gain/(loss) on disposition of investment securities). The Company has included information on these non-GAAP financial measures because the Company believes that investors may find it useful to have access to the same analytical tool used by management. As a result of merger and acquisition activity, the Company has recognized goodwill and other intangible assets in accordance with generally accepted accounting principles. Excluding the impact of goodwill and other intangibles in measuring asset and capital values for the ratios provided, along with other bank standard capital ratios, provides a framework to compare the capital adequacy of the Company to other companies in the financial services industry.   These non-GAAP measures should not be viewed as a substitute for operating results and other financial measures determined in accordance with GAAP. An item which management deems to be non-operating and excludes when computing these non-GAAP measures can be of substantial importance to the Company’s results for any particular quarter or year. The Company’s non-GAAP performance measures are not necessarily comparable to non-GAAP performance measures which may be presented by other companies. . Reconciliations of these non-GAAP financial measures to the most directly comparable GAAP financial measures are presented under “GAAP to Non-GAAP Reconciliations.” Reconciliations are included in the most recent Earnings Release, which can be located on our website here: http://ir.cambridgetrust.com/News/ .

Cambridge Bancorp Parent of Cambridge Trust Company Denis K. Sheahan Chairman, President and Chief Executive Officer 617-520-5520 Michael F. Carotenuto Executive Vice President and Chief Financial Officer 617-520-5520