Garmin Run Marathon Series - Thailand Half Marathon 2026

Garmin Run Marathon Series - Thailand Half Marathon 2026 marks a significant change for Garmin Run Thailand. After more than 6,300 runners joined the 2025 event in Bangkok, Garmin is taking its Thai race outside the capital for the first time, staging the 2026 edition in historic Phra Nakhon Si Ayutthaya. The race is part of the wider Garmin Run Marathon Series, which links 13 host cities across Asia and the United States. Runners who complete 10 of the 13 series races between 2022 and 2027 can apply for the series' customised 18K gold-plated completion medal.

All three road races start and finish at the Ayutthaya Tourist Center, housed in the old Ayutthaya City Hall. The half marathon starts first at 04:30, followed by the 10K at 05:00 and the 5K at 05:15. Published finish limits are 08:00 for the half marathon, 07:30 for the 10K and 06:45 for the 5K. Garmin publishes separate course-map graphics for each distance; runners should consult the current official maps for the final route rather than assume the three races use the same loop.

Race-day operations begin early. The event area and baggage service open at 03:00, Garmin's pacers are introduced at 03:45, and the half-marathon warm-up begins at 04:00 before runners enter the start area. Post-race food, drinks and fruit service begins at 06:00, with the overall awards ceremony scheduled for 06:30.

The organiser lists a minimum participant age of 16. Race-pack collection is on Saturday 5 December at the same Ayutthaya Tourist Center venue, one day before racing. Registration runs through 30 September 2026, subject to availability. The event combines a destination setting in Thailand's former capital with Garmin's international series format, while retaining accessible 5K and 10K options alongside the headline half marathon.