| 391 | 03 Oct 25 | 2025 Center of the Nation Series - Day 5 (ND) | 5K/10K | Bowman, ND |
| 392 | 04 Oct 25 | 2025 Center of the Nation Series - Day 6 (MT) | 5K/10K | Baker, MT |
| 393 | 19 Jul 25 | 2025 Cereal City Triathlon & Duathlon | triathlon | Battle Creek, MI |
| 394 | 19 Jul 25 | 2025 Challenge New Jersey State Triathlon - Sprint Saturday | triathlon | West Windsor, NJ |
| 395 | 19 Jul 25 | 2025 Charles M. Schulz-Sonoma County Airport Napa to Sonoma Wine Country Half Marathon & Rosé 5K | 5K | Napa, CA |
| 396 | 15 Jun 25 | 2025 Charleston Sprint Triathlon Series Race 1 | triathlon | Charleston, SC |
| 397 | 22 Jun 25 | 2025 Chattanooga Waterfront Triathlon | triathlon | Chattanooga, TN |
| 398 | 26 Jul 25 | 2025 Chesaning Chamber of Commerce Dry-Tri | triathlon | Chesaning, MI |
| 399 | 25 Oct 25 | 2025 Chessie Trail Marathon, Half Marathon, 10K, 5K, & 26.2 Relay | 10K/13.1/26.2/5K | Lexington, VA |
| 400 | 21 Jun 25 | 2025 Chesterfield Youth Triathlon | triathlon | Chesterfield, MO |
| 401 | 23 Aug 25 | 2025 Chicago Triathlon (Sunday) | triathlon | Chicago, IL |
| 402 | 16 Aug 25 | 2025 Chick-fil-A Cherokee County 5K | 5K | Canton, GA |
| 403 | 01 Aug 25 | 2025 Chile Harvest YOUTH Triathlon - FRIDAY | triathlon | Socorro, NM |
| 404 | 26 Jul 25 | 2025 Chisago Lakes Kids Triathlon - Saturday | triathlon | Chisago, MN |
| 405 | 27 Jul 25 | 2025 Chisago Lakes Triathlon - Sunday | triathlon | Chisago, MN |