| 256 | 14 Jun 25 | 2025 Black Butte Triathlon | triathlon | Corning, CA |
| 257 | 27 Sep 25 | 2025 Black Canyon Triathlon | triathlon | Montrose, CO |
| 258 | 28 Jun 25 | 2025 Black Diamond Triathlon | triathlon | Enumclaw, WA |
| 259 | 28 Nov 25 | 2025 Black Friday 5k/10k | 10K/5K | Herndon, VA |
| 260 | 21 Jun 25 | 2025 Blackfoot Kicker Triathlon | triathlon | Blackfoot, ID |
| 261 | 06 Sep 25 | 2025 Blackhawk YMCA Triathlon | triathlon | Waterloo, IA |
| 262 | 01 Sep 25 | 2025 Blackland Triathlon & Youth Triathlon (LABOR DAY) | triathlon | Plano, TX |
| 263 | 06 Sep 25 | 2025 Blake's Tinman Triathlon | triathlon | Reedsburg, WI |
| 264 | 12 Oct 25 | 2025 Block Island Half Marathon | Half Marathon | Block Island, RI |
| 265 | 10 May 25 | 2025 Block Island Shad Bloom 10 K Trail Run | 10K | Block Island, RI |
| 266 | 02 Aug 25 | 2025 Block Island Triathlon | triathlon | Block Island, RI |
| 267 | 18 May 25 | 2025 BoFish Triathlon | triathlon | Trumbull, CT |
| 268 | 02 Aug 25 | 2025 Boiling Springs Triathlon | triathlon | Boiling Springs, PA |
| 269 | 12 Oct 25 | 2025 Bolivar Live Triathlon | triathlon | Port Bolivar, TX |
| 270 | 30 Aug 25 | 2025 Bonney Lake Triathlon | triathlon | Bonney Lake, WA |