Seacoast Half Marathon

The Seacoast Half Marathon is an annual running event held in Portsmouth, New Hampshire, celebrating its 20th edition in 2025. The half marathon course starts and finishes at Portsmouth High School and winds through the scenic coastal communities of Rye and New Castle, showcasing the historic beauty of New Hampshire’s Seacoast. This local, charitable race stands out by donating 100% of its net proceeds to a deserving nonprofit organization in the Seacoast area.

Participants receive a long-sleeve race shirt and a medal. The 2025 beneficiary is the Birchtree Center, supporting individuals with behavioral challenges, autism, and related disabilities. Visit the organization's website for the most recent information.