| 15556 | 17 Aug 25 | 2025 Clayton Kids Triathlon | triathlon | Clayton, MO |
| 15557 | 10 Aug 25 | 2025 Classic City Sprint, Duathlon and Aquabike | triathlon | Athens, GA |
| 15558 | 10 Aug 25 | 2025 City of Edinburg Triathlon | triathlon | Edinburg, TX |
| 15559 | 01 Sep 25 | 2025 Cincinnati Aruna Run | 10K/1M/5K | Cincinnati, OH |
| 15560 | 06 Sep 25 | 2025 Chroma Team Racing Championship . . | triathlon | Nashville, TN |
| 15561 | 26 Jul 25 | 2025 Christmas in July 5k/Half | 13.1/5K | Washington, DC |
| 15562 | 24 Dec 25 | 2025 Christmas Eve 5k/10k | 10K/5K | Washington, DC |
| 15563 | 27 Jul 25 | 2025 Chisago Lakes Triathlon - Sunday | triathlon | Chisago, MN |
| 15564 | 26 Jul 25 | 2025 Chisago Lakes Kids Triathlon - Saturday | triathlon | Chisago, MN |
| 15565 | 01 Aug 25 | 2025 Chile Harvest YOUTH Triathlon - FRIDAY | triathlon | Socorro, NM |
| 15566 | 16 Aug 25 | 2025 Chick-fil-A Cherokee County 5K | 5K | Canton, GA |
| 15567 | 23 Aug 25 | 2025 Chicago Triathlon (Sunday) | triathlon | Chicago, IL |
| 15568 | 25 Oct 25 | 2025 Chessie Trail Marathon, Half Marathon, 10K, 5K, & 26.2 Relay | 10K/13.1/26.2/5K | Lexington, VA |
| 15569 | 26 Jul 25 | 2025 Chesaning Chamber of Commerce Dry-Tri | triathlon | Chesaning, MI |
| 15570 | 19 Jul 25 | 2025 Charles M. Schulz-Sonoma County Airport Napa to Sonoma Wine Country Half Marathon & Rosé 5K | 5K | Napa, CA |