Cambridge Half Marathon + 5K

Registration is now open for the annual Cambridge Half Marathon and 5K at CambridgeSide.

Saturday, October 31, 2026: The Cambridge 5K is the kickoff to race weekend and will take place on Saturday, October 31, 2026. It's a 3.1 mile course that starts and ends at CambridgeSide. It's a quick out and back along the Charles River that will have you in awe of the Boston skyline. Race starts at 10am.

Sunday, November 1, 2026: The Cambridge Half Marathon is a 13.1 mile USATF certified course that starts and finishes at CambridgeSide. It is a fast and flat course along Memorial Drive featuring views of the Charles River, MIT, John W. Weeks Footbridge, Harvard University Stadium, and more. Race starts at 7am.

Click here for Race Information and Registration.

For sponsorship or volunteer opportunities, please email CSinfo@NEDevelopment.com. 

The Cambridge Half Marathon and 5K at CambridgeSide supports many local charities including Cambridge Camping, City of Cambridge Scholarship Fund, and more!

Ready for a challenge? Sign up to run both the Cambridge Half Marathon and 5K during race weekend. Cambridge Half Marathon + 5K Challenge participants will receive both the Cambridge Half Marathon quarter zip as well as the Cambridge 5K long sleeved technical shirt with their registrations. Learn more here.