Half Marathons in Missouri 2026 | Upcoming Races & Dates | My Next Race

There are 5 half marathons in Missouri scheduled for 2026. The next is the 2026 Matt Mason "Cowboy UP" Triathlon/Duathlon in Smithville on July 26. Missouri half marathons run primarily July through October.

Ballwin Triathlon

Sun, Jul 19 · Ballwin, MO Ballwin

SPRINT INDIVIDUAL TRI SINGLE Wave 2 - STARTS 7:00AMSPRINT INDIVIDUAL TRI DOUBLE Wave 1 - STARTS 6:45AMSPRINT RELAY TRI SINGLE Wave 4 - STARTS 8:30AM +3

From $25 Open 7 spots left

2026 Matt Mason "Cowboy UP" Triathlon/Duathlon

Sun, Jul 26 · Smithville, MO Smithville

Short Course (Individual)Short Course (Relay Team of 2-3 participants))Short Course Duathlon +4

From $55 Open 32 spots left

Giro Della Lou

Sun, Sep 6 · Saint Louis, MO Saint Louis

Short Ride - 18 MilesMedium Ride - 31 MilesLong Ride - 51 Miles

From $40 Open

MIDNIGHT Rat Race - UNSANCTIONED

Fri, Oct 16 · Springfield, MO Springfield

Half-Marathon-ish

From $45 Open 55 spots left

The Innsbrook Half Marathon & 10k

Sat, Oct 24 · Innsbrook, MO Innsbrook

Innsbrook Half MarathonInnsbrook 10k

From $45 Open