| 12586 | 21 Jun 26 | 2026 Bozeman Triathlon | triathlon | Bozeman, MT |
| 12587 | 26 Dec 26 | 2026 Boxing Day 5k/10k | 10K/5K | Annandale, VA |
| 12588 | 28 Jun 26 | 2026 Boulder Sunrise Triathlon | triathlon | Boulder, CO |
| 12589 | 12 Jul 26 | 2026 Boulder Peak Triathlon | triathlon | Boulder, CO |
| 12590 | 27 Jun 26 | 2026 Bottomless Triathlon | triathlon | Roswell, NM |
| 12591 | 23 Aug 26 | 2026 Boston Triathlon | triathlon | Boston, MA |
| 12592 | 25 Apr 26 | 2026 Booking It Through the Bluff Triathlon & 10K | triathlon | Hokes Bluff, AL |
| 12593 | 12 Apr 26 | 2026 Book Bounce 5k/10k | 10K/5K | Arlington, VA |
| 12594 | 26 Apr 26 | 2026 Bluemont Station Brewery & Winery 5k | 5K | Bluemont, VA |
| 12595 | 09 May 26 | 2026 Block Island Shad Bloom 10 K Trail Run | 10K | Block Island, RI |
| 12596 | 11 Oct 26 | 2026 Block Island Half Marathon | Half Marathon | Block Island, RI |
| 12597 | 25 Jul 26 | 2026 Black Squirrel Scurry Triathlon | triathlon | Merrill, WI |
| 12598 | 27 Nov 26 | 2026 Black Friday 5k/10k | 10K/5K | Herndon, VA |
| 12599 | 20 Jun 26 | 2026 Black Butte Triathlon | triathlon | Corning, CA |
| 12600 | 12 Apr 26 | 2026 Bill Bone OLYMPIC Triathlon | triathlon | West Palm Beach, FL |