| 12631 | 28 Mar 26 | 2026 Culpeper Airport 5k | 5K | Culpeper, VA |
| 12632 | 31 May 26 | 2026 Crooked Run Valley 5k & 10k | 10K/5K | Delaplane, VA |
| 12633 | 26 Jul 26 | 2026 Crescent City Triathlon | triathlon | Crescent, CA |
| 12634 | 29 Nov 26 | 2026 Cranberry Crawl Turkey Trot 5k/5-Miler/10M | 10M/5K/5M | Washington, DC |
| 12635 | 11 Jul 26 | 2026 Cool Sommer Mornings Triathlon Series #2 | triathlon | Clermont, FL |
| 12636 | 13 Jun 26 | 2026 Cool Sommer Mornings Tri Series #1 | triathlon | Clermont, FL |
| 12637 | 28 Mar 26 | 2026 Consider How the Wildflowers Grow 1M 5K 10K 13.1 26.2 | Virtual | Mobile, AL |
| 12638 | 14 Jun 26 | 2026 Columbia River Half Iron | triathlon | Vantage, WA |
| 12639 | 12 Apr 26 | 2026 Columbia Gateway Duathlon | triathlon | Columbia, MD |
| 12640 | 06 Jun 26 | 2026 Colorado Triathlon | triathlon | Boulder, CO |
| 12641 | 02 Aug 26 | 2026 Coca Strong 5k/10k Hope in Every Step | 10K/5K | Valley Cottage, NY |
| 12642 | 20 Jun 26 | 2026 Clemson Triathlon | triathlon | Seneca, SC |
| 12643 | 13 Jun 26 | 2026 Claude Moore 5k & 10k | 10K/5K | Sterling, VA |
| 12644 | 27 Mar 26 | 2026 CLASH Miami Triathlon - Sunday Events | triathlon | Homestead, FL |
| 12645 | 29 Mar 26 | 2026 CLASH Endurance Coastal Mississippi | triathlon | Gulfport, MS |