Marathons in Boulder, Colorado
1 upcoming race is listed in Boulder, including 1 marathon and 1 half marathon. The next is Boulder Marathon on October 4, 2026.
October has the most races. Race pages link the official source where we have one. Confirm dates and prices with the organizer before you register.
1
Races listed
1
Marathons
October
Busiest month
25 May
Last updated
| Date | Race | Distances | From |
|---|---|---|---|
| 4 Oct 2026 04Oct 26 | Boulder Marathon | 42.2K · 21.1K · 10K | $85–$125 |
Around Boulder
This is the most detailed level of the directory. Widen the search to the surrounding region.
Common questions
When is the next race in Boulder?
Boulder Marathon on October 4, 2026. The table above lists every upcoming race in date order.
Which months are busiest in Boulder?
October (1), counting every upcoming race listed in Boulder.
Which distances can I run in Boulder?
The listed races include 1 marathon, 1 half marathon and 1 10K. Many events offer more than one distance on the same day.
How do I confirm a race’s details?
Open the race page and check its provenance ledger, which shows where each fact came from. Then confirm the date, price and entry rules with the organizer before you register or book travel.
Spotted something wrong on this page?
Dates and prices move · tell us and we check the organizer’s source