Boston Marathon 2025 Registration Window Online. The boston marathon registration window for the 2025 boston marathon opens on september 1, 2023, and closes on september 13, 2024. The qualifying window for the boston marathon 2025 will.

Any athlete who has achieved a currently valid boston marathon qualifying time may submit a registration application during registration week. The qualifying window for the 129th boston marathon, scheduled to take place on april 21, 2025, began on september 1, 2023.