| COILMASTER 1336284 · TMA721011 | Signode International IP Holdings LLC | 7 Machines | Registered | 2008 |
| CELLMASTER 2013177 · TMA1264928 | TECNIPLAST INC. | 19 Building | Registered | 2024 |
| CELLMASTER 0734403 · TMA442311 | an individual | 9 Electronics | Registered | 1995 |
| CLINGMASTER 0366131 · TMA198281 | AEP INDUSTRIES INC. (A DELAWARE CORPORATION) | 17 Rubber | Registered | 1974 |
| CLAYMAKER 2262002 · TMA1281338 | CLAYNOSAURZ INC. | 28 Toys | Registered | 2025 |
| CLAYMAKER 2262000 · TMA1281337 | CLAYNOSAURZ INC. | 9 Electronics35 Advertising41 Education+1 | Registered | 2025 |
| CLEANSTER 2360224 | Cleanster Technologies Inc. | 9 Electronics42 Science | Pending | 2024 |
| CLINICMASTER 1568103 · TMA851831 · design | LES SYSTÈMES ADDATECH INC. | 9 Electronics16 Paper21 Housewares+5 | Registered | 2013 |
| CLINICMASTER 1568102 · TMA851830 | LES SYSTÈMES ADDATECH INC. | 9 Electronics16 Paper21 Housewares+5 | Registered | 2013 |
| COLLEMASSARI 2287705 · design | Owner not shown | 29 Meat33 Wine43 Restaurants | Pending | 2023 |
| COLLEMASSARI 2287704 | Owner not shown | 29 Meat33 Wine43 Restaurants | Pending | 2023 |
| CLAIMCENTER 2196245 | Guidewire Software, Inc. | 9 Electronics42 Science | Pending | 2022 |
| coolmax 2260153 · TMA1277969 | Owner not shown | 34 Tobacco | Registered | 2024 |
| CLENSTELFIO 2249095 · TMA1261944 | Owner not shown | 5 Pharmaceuticals | Registered | 2024 |
| CALONOX 2237128 · TMA1251608 | Owner not listed | 9 Electronics | Registered | 2024 |
| CLAYNOSAURZ 2234825 · TMA1256734 | CLAYNOSAURZ INC. | 9 Electronics21 Housewares25 Clothing+4 | Registered | 2024 |
| CLINCHER 2225755 · TMA1251233 | NORD GEAR LIMITED/ENGRENAGES NORD LIMITEE | 7 Machines | Registered | 2024 |
| CLEANGUARD 2224923 · TMA1250151 | The Procter & Gamble Company | 5 Pharmaceuticals | Registered | 2024 |
| COOLOONG 2217840 · TMA1246728 · design | Cooloong Canada Inc. | 35 Advertising | Registered | 2024 |
| CLINISTIX 2215689 · TMA1233975 | SIEMENS HEALTHCARE DIAGNOSTICS INC. | 1 Chemicals5 Pharmaceuticals | Registered | 2024 |
| CLEANSHIELD 2212364 · TMA1243101 | Kimberly-Clark Worldwide, Inc. | 5 Pharmaceuticals | Registered | 2024 |
| CylanceAVERT 2209807 · TMA1224664 | Cylance Inc. | 9 Electronics42 Science | Registered | 2024 |
| CylancePERSONA 2209806 · TMA1224663 | Cylance Inc. | 9 Electronics42 Science | Registered | 2024 |
| CylanceGATEWAY 2209805 · TMA1224662 | Cylance Inc. | 9 Electronics42 Science | Registered | 2024 |
| Caliwiness 2201448 · TMA1238728 | Chengdu Jiajuxiankang Trading Co., Ltd. | 21 Housewares | Registered | 2024 |