SEAFAIR TRIATHLON
SEWARD PARK, SEATTLE
JULY 20, 2025
SPRINT | SUPER SPRINT | DUATHLON
2 & 3 PERSON SPRINT RELAY | KIDS TRIATHLON
RACE REGISTRATION NOTIFICATION
The Triathlon is very close to capacity. If you click the “register” button and are unable to sign up for your race distance/discipline it is because we are currently at capacity. Check back periodically – as participants choose to defer their registration to 2026 a spot will open up. It is first come first serve. We hope to see you at the event!
The 2025 Seafair Triathlon will once again call Seward Park home on July 20th!
We are SO excited to host over 1,500 triathletes at Seward Park this year. Seattle’s ONLY Triathlon will once again take over the shores of Lake Washington this summer and Seward Park is the perfect backdrop for this flat, fast and picturesque triathlon course in the shadows of Downtown Seattle.
Whether you’ve completed a triathlon before or told yourself one day you might, this is your year and this is your triathlon. Featuring small wave sizes, multiple distance options, and team relay competitions, the Seafair Triathlon prides itself on hosting a range of participants from elite level triathletes to beginners getting their first taste of triathlon competition.
Haven’t tried a TRI before? This is the year to start!