Boston Mini Marathon, 5K, Relay & Fun Run

Boston Mini Marathon, 5K, Relay & Fun Run is run in downtown Boston, Massachusetts, on October 31, 2026. The half marathon starts at 8 a.m., the 5K race at 8:15 a.m. and the 5K walk at 8:30 a.m. The certified, professionally timed course follows paved paths with aid stations placed along the way, and includes rolling hills and a demanding final climb.

That closing hill is the detail to train for. Put a hard climb into the last two miles of a long run every couple of weeks so the finish feels rehearsed rather than punishing, and hold something back through the rolling middle section. The 5K, run or walked, is the friendlier option if downtown hills are new to you. Nutritious food and drinks are on hand afterwards in a festive atmosphere, and the venue offers accessible facilities.