| | | | | | | | | | | | | | |
| Subsidiaries | | Former Names at September 30, 2020 | | Location |
| CMC Materials Global Corporation | | Cabot Microelectronics Global Corporation | | Delaware, U.S. |
| NexPlanar Corporation | | | | Delaware, U.S. |
| QED Technologies International, Inc. | | | | Delaware, U.S. |
| CMC Materials Japan KK | | Cabot Microelectronics Japan KK | | Japan |
| CMC Materials KK | | Nihon Cabot Microelectronics KK | | Japan |
| CMC Materials B.V. | | Cabot Microelectronics B.V. | | Netherlands |
| CMC Materials Asia Pte. Ltd. | | Cabot Microelectronics Singapore Pte. Ltd. | | Singapore |
| CMC Materials Korea, LLC | | Hanguk Cabot Microelectronics, LLC | | South Korea |
| CMC Materials Taiwan Co., Ltd. | | Epoch Material Co., Ltd. | | Taiwan |
| Shanghai Cabot Microelectronics Co. Ltd. | | | | China |
| CMC Materials KMG Corporation | | KMG Chemicals, Inc. | | Texas, U.S. |
| KMG-Bernuth, Inc. | | | | Delaware, U.S. |
| KMG de Mexico SA de CV | | | | Mexico |
| CMC Materials EC, Inc. | | KMG Electronic Chemicals, Inc. | | Texas, U.S. |
| CMC Materials Italia SrL | | KMG Italia Srl | | Italy |
| CMC Materials Luxembourg Holdings S.a.r.l. | | KMG Electronic Chemicals Luxembourg Holdings S.a.r.l. | | Luxembourg |
| CMC Materials France SAS | | KMG Electronic Chemicals SAS | | France |
| CMC Materials UPC SAS | | KMG Ultra Pure Chemicals SAS | | France |
| CMC Materials EC Pte. Ltd. | | KMG Electronic Chemicals, Pte. Ltd. | | Singapore |
| CMC Materials Singapore Pte. Ltd. | | KMG Singapore Pte. Ltd. | | Singapore |
| CMC Materials SDN BHD | | KMG Ultra Pure Chemicals SDN BHD | | Malaysia |
| CMC Materials UK Limited | | KMG Electronic Chemicals Limited | | United Kingdom |
| CMC Materials UPC Limited | | KMG Ultra Pure Chemicals Limited | | United Kingdom |
| CMC Materials Sealweld Canada, Inc. | | KMG Industrial Lubricants Canada, Inc. | | British Columbia, Canada |
| KMG Val-Tex, LLC | | | | Texas, U.S. |
| Sealweld Corporation (2003), Inc. | | | | Nevada, U.S. |
| Sealweld (USA), Inc. | | | | Texas, U.S. |
| KMG-Flowchem, Inc. | | | | Delaware, U.S. |
| Flowchem LLC | | | | Delaware, U.S. |
| FLX Inc. | | | | Texas, U.S. |