The Great Bay 5K is excited to hold its 27th annual race in 2025!  The GB5K is the final race in the popular Seacoast Road Race Series and supports the non-profit Great Bay Stewards. The course passes the shores of Great Bay, and is a fun, fast, scenic, and mostly downhill event.  In 2025, we are pleased to bring back the Great Bay 55K Challenge - run the entire 55 kilometers in one day, or complete the total distance anytime between October 1 - 25. 

Wheelchair racers are welcome and will start at 8:45 a.m, prior to the 9 a.m. runner/walker start. No motorized wheelchairs are permitted, and wheelchair racers are responsible for maintaining their own equipment

Participants in the 5K events will receive a long-sleeve race shirt and everyone will get a bib with tear strips that you can take to select establishments for free beer/cider . Please keep in mind that you must register by October 1 to get a race shirt. People who register after that may claim a shirt if any are left over on race day.

All proceeds from the Great Bay 5K go to the non-profit Great Bay Stewards, which supports conservation, education, community outreach, stewardship, and research of the Great Bay estuary.