Marathons in Japan

Planning a marathon in Japan for 2026? Run Atlas lists 11 upcoming 42 km races — from big city events to scenic regional courses.

Whether you are chasing a personal best or your first finish line, comparing dates early helps you secure a start slot and build your training block around the right peak.

Use the calendar below to browse marathons month by month. December 2026 is a busy month in our listings when several races cluster on weekends.

Many runners look for a flagship race in the capital. Tokyo often hosts the most iconic marathon in Japan, but smaller towns offer quieter starts and fast, flat profiles.

Check registration windows as soon as you pick a date — popular spring and autumn weekends fill up months ahead.

World Marathon Majors in Japan are highlighted separately — bookmark your favourites on Run Atlas and set a RaceAlert when registration opens.