Exhibit 23
CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM
We consent to the incorporation by reference in Registration Statement Nos. 333- 177176, 333-19103, 333-19099, 333-96881, 333-134134, 333-158991, 333-161253, 333-181391, 333-204365, and 333-216707 on Forms S-8 of our reports dated November 22, 2019, relating to the financial statements of Cabot Corporation, and the effectiveness of Cabot Corporation’s internal control over financial reporting, appearing in the Annual Report on Form 10-K of Cabot Corporation for the year ended September 30, 2019.
/s/ Deloitte & Touche LLP
Boston, Massachusetts
November 22, 2019