2021 Seafair Triathlon

Register for 2021 Seafair Triathlon

Welcome to the 2021 Seafair Triathlon! 

Each participant of the Seafair Triathlon, with entry, will receive a participant shirt, finisher medal, and personalized bib! 

The Northwest's premier triathlon will take place on the shores of Lake Sammamish at Lake Sammamish State Park. Offering participants multiple disciplines on a flat, fast and picturesque triathlon course throughout Lake Sammamish, Issaquah and Sammamish. This race is a must do for all triathletes in the northwest. 

The event offers participants a unique opportunity to participate in a sprint distance triathlon or super sprint distance in an urban setting. Swimming in a protected cove, riding on closed roadways and running through Lake Sammamish State Park, this is the Pacific Northwest’s premier triathlon. 

Offering a Kids Triathlon as well, there is a distance for everyone in the family at the Seafair Triathlon! Join us in 2021 at the Seafair Triathlon with over 1,400 health enthusiasts taking part in the event.