Profile: Key Statistics: (Data as of 12.31.18) S&T Bancorp, Inc. is a $7.3 billion financial holding company headquartered in Indiana, PA, located Stock Price $37.84 Total Assets (in $ millions) $7,252 about 55 miles northeast of Pittsburgh, PA. Market Cap (in $ billions) $1.3 Common BV/Share $26.98 Founded in 1902 with a single location in Dividend Yield (annualized) 2.85% Indiana, PA, S&T Bancorp, Inc. has Tangible BV/Share (non-GAAP) $18.63 Price/Earnings (LTM) 12.6 expanded to five markets including Western PA, Central PA, Northeast OH, Central OH and Upstate NY. S&T provides a full range of financial services to individuals and businesses in PA and Northeast OH and has loan production offices in Central OH and Upstate NY. Investment Thesis: S&T Operates in • Above peer performance Five Markets • Demonstrated expense discipline and efficiency • Organic growth • Strategic and effective mergers and expansion • Stable markets with     long term oil and gas benefit • Sound asset quality • The Right Size Recent Mergers and Expansions: November 16, 2016 March 4, 2015 S&T Bank loan production office opens S&T Bancorp merges with Integrity on North Shore Pittsburgh in Western Bancshares in Central PA, adding PA. 8 offices, $789 million in loans, and $722 million in deposits. November 1, 2016 S&T Bank branch relocates to expanded January 21, 2014 facility in Northeast OH. S&T Bank loan production office opens to service Central OH March 23, 2015 S&T Bank loan production office opens to service Upstate NY.

Senior Management: Financial Highlights: Todd D. Brice Chief Executive Officer 2017 Excludes David G. Antolik 2018 2017 DTA(1) 2016 2015 President and Chief Lending Officer Net Income (in $ thousands) $105,334 $72,968 $86,401 $71,392 $67,081 Mark Kochvar Diluted Earnings per Share $3.01 $2.09 $2.47 $2.05 $1.98 Chief Financial Officer Dividends Declared per Share $0.99 $0.82 $0.77 $0.73 David P. Ruddock Chief Operating Officer Total Assets (in $ millions) $7,252 $7,060 $6,943 $6,318 Rebecca A. Stapleton Chief Banking Officer Total Loans (in $ millions) $5,949 $5,766 $5,615 $5,063 Investor Relations Contact: Total Deposits (in $ millions) $5,674 $5,428 $5,272 $4,877 Mark Kochvar S&T Bancorp, Inc. Return on Average Assets 1.50% 1.03% 1.22% 1.08% 1.13% 800 Philadelphia Street Indiana, PA 15701 Return on Average Equity 11.60% 8.37% 9.90% 8.67% 8.94% 724.465.4826 mark.kochvar@stbank.com Return on Tangible Equity (non-GAAP) 17.14% 12.77% 15.08% 13.71% 14.39% For more information visit Net Interest Margin (FTE) (non-GAAP) 3.64% 3.56% 3.47% 3.56% stbancorp.com or stbank.com. Common stock traded on the NASDAQ Nonperforming Assets/ Loans + OREO 0.83% 0.42% 0.77% 0.71% under the symbol STBA Allowance for Loan Losses/ Total Loans 1.03% 0.98% 0.94% 0.96% Analyst Coverage: Net Loan Charge-offs / Average Loans 0.18% 0.18% 0.25% 0.22% The following analysts published research about S&T Bancorp, Inc. in 2019. Boenning & Scattergood Risk-based Capital - Total 13.21% 12.55% 11.86% 11.60% Matthew Schultheis • 610.832.5290 Tangible Common Equity/ Tangible mschultheis@boenninginc.com Assets (non-GAAP) 9.28% 8.72% 8.23% 8.24% DA Davidson Russell Gunther • 212.223.5403 rgunther@dadco.com Total Annualized Shareholder Return Keefe, Bruyette & Woods Includes reinvested dividends Collyn Gilbert • 973.549.4092 (Data as of 12.31.18) collyn.gilbert@kbw.com Piper Jaffray 1 YR 3 YR 5 YR 10 YR Matthew Breese • 617.654.0728 matthew.m.breese@pjc.com STBA (2.66)% 9.76% 11.16% 3.55% Raymond James S&P 600 Bank (10.25)% 9.13% 7.55% 7.05% Daniel Cardenas • 312.655.2986 daniel.cardenas@raymondjames.com NASDAQ Bank (16.09)% 6.84% 6.85% 7.19% S&P 500 (4.37)% 9.24% 8.48% 13.10% Source: Bloomberg (1)These are non-GAAP numbers that adjust for the effects of a one-time, non-cash re-measurement of $13.4 million of our deferred tax asset in 2017. This document may contain “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995. Such statements involve risks and uncertainties that could cause actual results to differ materially from the results discussed in these statements. These risks are detailed in the company’s latest form 10- K filed with the Securities and Exchange Commission and any subsequently filed reports containing updates to these risks. Any such forward-looking statement or other information herein speaks only as of the particular dates referenced or the date such information or statement is made, and S&T undertakes no obligation to update any such information. This document also contains or references, certain non-GAAP financial measures. Although S&T believes that these measures enhance investors’ understanding of S&T’s business and performance, these non-GAAP financial measures should not be considered an alternative to GAAP, and should be read in conjunction with the audited financial statements and analysis as presented in the Annual Report on Form 10-K as well as the unaudited financial statements and analyses as presented in the respective Quarterly Reports on Forms 10-Q for S&T Bancorp, Inc. and subsidiaries.