| 436 | 16 Aug 25 | 2025 Courage Triathlon . . | triathlon | Westwood, CA |
| 437 | 14 Sep 25 | 2025 Craig Ranch McKinney Triathlon | triathlon | McKinney, TX |
| 438 | 30 Nov 25 | 2025 Cranberry Crawl Turkey Trot 5k/5-Miler/10M | 10K/13.1/5K | Washington, DC |
| 439 | 27 Jul 25 | 2025 Crescent City Triathlon | triathlon | Crescent, CA |
| 440 | 29 Jun 25 | 2025 Crestwood Kids Triathlon | triathlon | Saint Louis, MO |
| 441 | 26 Jul 25 | 2025 Crofton's Dam Race | triathlon | Crofton, NE |
| 442 | 08 Jun 25 | 2025 Crooked Run Valley 5k/10k | 10K/5K | Delaplane, VA |
| 443 | 26 Oct 25 | 2025 Crown Point Marathon/Half-Marathon, Team Relays, 8K & 5K Runs | 5K/8K | San Diego, CA |
| 444 | 04 May 25 | 2025 Crystal Beach Triathlon . . | triathlon | Crystal Beach, TX |
| 445 | 24 May 25 | 2025 Crystal River Triathlon Series - Sprint #1 | triathlon | Crystal River, FL |
| 446 | 07 Jun 25 | 2025 Culpeper Airport 5k | 5K | Culpeper, VA |
| 447 | 26 Jul 25 | 2025 Culpeper Triathlon | triathlon | Culpeper, VA |
| 448 | 07 Aug 25 | 2025 Cupertino Splash & Dash - AUGUST 7 | triathlon | Cupertino, CA |
| 449 | 05 Jun 25 | 2025 Cupertino Splash and Dash . . | triathlon | Cupertino, CA |
| 450 | 21 Jun 25 | 2025 Cure Coats' 5K | 5K | San Francisco, CA |