| 301 | 16 Aug 25 | 2025 Chick-fil-A Cherokee County 5K | 5K | Canton, GA |
| 302 | 13 Apr 25 | 2025 Chickahominy Chase 5k/10k | 10K/5K | Williamsburg, VA |
| 303 | 01 Aug 25 | 2025 Chile Harvest YOUTH Triathlon - FRIDAY | triathlon | Socorro, NM |
| 304 | 26 Jul 25 | 2025 Chisago Lakes Kids Triathlon - Saturday | triathlon | Chisago, MN |
| 305 | 27 Jul 25 | 2025 Chisago Lakes Triathlon - Sunday | triathlon | Chisago, MN |
| 306 | 26 Apr 25 | 2025 Choose To Move... | triathlon | Fishers, IN |
| 307 | 06 Sep 25 | 2025 Chroma Team Racing Championship . . | triathlon | Nashville, TN |
| 308 | 14 Jun 25 | 2025 Cicero Triathlon | triathlon | Cicero, IN |
| 309 | 28 Mar 25 | 2025 CLASH Miami Triathlon . . | triathlon | Homestead, FL |
| 310 | 10 Aug 25 | 2025 Classic City Sprint, Duathlon and Aquabike | triathlon | Athens, GA |
| 311 | 28 Jun 25 | 2025 Claude Moore 5k/10k | 10K/5K | Sterling, VA |
| 312 | 17 Aug 25 | 2025 Clayton Kids Triathlon | triathlon | Clayton, MO |
| 313 | 19 Jul 25 | 2025 Clear Lake Sprint and Olympic Triathlons | triathlon | Fremont, IN |
| 314 | 21 Jun 25 | 2025 Clemson Triathlon | triathlon | Seneca, SC |
| 315 | 22 Jun 25 | 2025 Clinton Lake Sprint Triathlon | triathlon | DeWitt, IL |