Exhibit 99.1 CABOT CORP REPORTS SECOND QUARTER FISCAL 2024 RESULTS Diluted earnings per share (“EPS”) of $1.49 and Adjusted EPS of$1.78 BOSTON (May 6, 2024)-- Cabot Corporation (NYSE: CBT) today announced results for its second quarter of fiscal year 2024. Key Highlights • Diluted EPS of $1.49 and adjusted EPS of$1.78, which represents a 34% increase in Adjusted EPS as compared to the same quarter in the prior year • Reinforcement Materials segment EBIT of $149 million; up 22% compared to the same quarter ...