RPM 2020 Proxy Statement

2628 PEARL ROAD • P.O. BOX 777 MEDINA, OHIO 44258 NOTICE OF ANNUAL MEETING OF STOCKHOLDERS Notice is hereby given that the Annual Meeting of Stockholders of RPM International Inc. will be on Thursday, October 8, 2020, at 2:00 p.m., Eastern Daylight Time, for the following purposes: (1) To elect four Directors to serve in Class III of the Board; (2) To hold a non-binding, advisory vote to approve the Company’s executive compensation; (3) To ratify the appointment of Deloitte & Touche LLP as the Company’s independent registered public accounting firm for the fiscal year ending May 31, 2021; and (4) To transact such other business as may properly come before the Annual Meeting or any adjournment or postponement thereof. Due to the public health impact of the Covid-19 pandemic and to support the health and well-being of our stockholders, employees and their families, this year’s Annual Meeting will be held in a virtual meeting format only, through a live webcast. Stockholders will not be able to attend the Annual Meeting physically in person in light of public health concerns. Stockholders will be able to vote and submit questions by visiting www.virtualshareholdermeeting.com/RPM2020 and participating live in the webcast. A secure control number that will allow you to participate in the meeting electronically can be found on the enclosed proxy card. Holders of shares of Common Stock of record at the close of business on August 14, 2020 are entitled to receive notice of and to vote at the Annual Meeting. By Order of the Board of Directors. E DWARD W. M OORE Secretary August 26, 2020 Please fill in and sign the enclosed Proxy and return the Proxy in the envelope enclosed herewith.