| 3676 | 07 Jun 26 | Corrib Classic 5K | 5K | West Roxbury, MA |
| 3677 | 24 Oct 26 | Corryton Possum Chase | 2M/4M | Corryton, TN |
| 3678 | 05 Dec 26 | Corsicana YMCA Jingle Bell Jog | 1M/5K | Corsicana, TX |
| 3679 | 13 Jun 26 | Corteau Vineyards Wine Run 5K | 5K | Mechanicsville, MD |
| 3680 | 04 Jul 26 | Corunna Firecracker 5K | 5K | Corunna, MI |
| 3681 | 27 Sep 26 | Corvallis Fall Festival Run | 5K/10K | Corvallis, OR |
| 3682 | 06 Jun 26 | Cosley Zoo Run for the Animals | 5K/10K | Wheaton, IL |
| 3683 | 26 Sep 26 | Cossatot River Trail Run | ['Half Marathon'/ 'Marathon'] | Wickes, AR |
| 3684 | 31 Oct 26 | Costumed Creature Crawl 5K Trail Run | 1M/5K | Beach Lake, PA |
| 3685 | 06 Jun 26 | Cottonmouth Beerlay & 8 Mile Solo | 8M | Greenville, SC |
| 3686 | 27 Nov 26 | Cottonwood Heights Thanksgiving Day 5K | 5K | Cottonwood Heights, UT |
| 3687 | 31 Oct 26 | Cougar Mountain Trail Run Series | 5K/7.6M/19.5M/50K | Bellevue, WA |
| 3688 | 11 Jul 26 | Cougar Mountain Trail Run Series | 5K/10.8M/19.5M | Newcastle, WA |
| 3689 | 13 Jun 26 | Cougar Mountain Trail Run Series #2 | 5K/8.2M/14.5M | Newcastle, WA |
| 3690 | 08 Aug 26 | Cougar Mountain Trail Run Series #4 | 5K/14.5M/26.2M | Newcastle, WA |