Great South Bay Run Half Marathon
Four decades of South Shore racing move several hundred runners through downtown Bay Shore and the Brightwaters canals to a finish facing Fire Island.
Every link above goes to the race, its timing provider, or an official registration partner. Last checked July 28, 2026.
Quick facts
- USATF certified half marathon starting at 7:30am from Bay Shore Marina Park.
- Half marathon field regularly runs several hundred deep.
- Half marathon, 10K, and 5K share the same start and finish area.
- Long standing South Shore fixture with more than 40 editions run.
2026 Great South Bay Run Half Marathon registration
Registration for the 2026 Great South Bay Run Half Marathon runs through the official registration page at runsignup.com.
About the Great South Bay Run Half Marathon
One of the older half marathons on Long Island's South Shore, this race has run since the mid 1980s and still pulls the deepest half marathon field in its corner of Suffolk County. The route leans on neighborhood character, with the lakes and canals of Brightwaters carrying the middle miles.
Course
Start and finish are at Bay Shore Marina Park. The USATF certified half marathon runs through the historic downtown, past homes along the Brightwaters Lakes, Cascades, and Canals, and closes with open water views of the Great South Bay.
Race-day weather
Early October on the South Shore is usually cool and breezy, with morning temperatures in the 50s. Wind off the bay bites hardest on the exposed finishing stretch near the marina.
Past Great South Bay Run Half Marathon dates and results
| Year | Date | Status | Results |
|---|---|---|---|
| 2026 | Saturday, October 3, 2026 | Upcoming | — |
Great South Bay Run Half Marathon FAQ
When is the Great South Bay Run Half Marathon?
The 2026 Great South Bay Run Half Marathon is on Saturday, October 3, 2026.
How do I register for the Great South Bay Run Half Marathon?
Register for the Great South Bay Run Half Marathon through the official registration link: marathonscout.com/go/great-south-bay-run-half-marathon/register. It opens the race registration page at runsignup.com.
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