Lake Biwa Marathon

The Osaka-Lake Biwa Mainichi Marathon (びわ湖毎日マラソン, Biwako Mainichi Marason) was a marathon race held in Otsu, Shiga, Japan. It was one of the prominent marathons in Japan. It was a male only competition and had IAAF Gold Label status.^[1] It was first held in 1946 and, having taken place every year since then, it was Japan's oldest annual marathon race.^[2] The early editions of the race were held in Osaka until a switch to Tokyo occurred for the 1963–64 marathons, and all subsequent races thereafter were held in Shiga Prefecture, starting in Ōtsu fronting Lake Biwa, where the race received its name. It was sponsored by Mainichi and was known simply as the Mainichi Marathon for a period.^[3] The final race was held in 2021.^[4]

Lake Biwa Marathon
2015 Lake Biwa Marathon
Date	Early March
Location	Ōtsu, Shiga, Japan
Event type	Road
Distance	Marathon
Primary sponsor	SEI K-Opticom Corporation (2010–)
Established	1946
Course records	2:04:56 (2021) Kengo Suzuki
Official site	Lake Biwa Marathon
Participants	325 (2021)

The race began and ended at the Ojiyama Stadium.^[1] The Lake Biwa Marathon was selected as the Japanese national marathon championships on dozens of occasions, starting in 1960.^[3] The course record for the competition was 2:04:56 hours, set by Kengo Suzuki at the final 2021 edition.^[4] The 2021 race was also noteworthy for having 29 runners finish in under 2:09:00 and 42 runners finish under 2:10:00.^[5]

The race was merged into the Osaka Marathon by the JAAF. The elite men's race at the Osaka Marathon for 2022 was designated by officials as the 77th Annual Lake Biwa Marathon, while the other races were billed as the Osaka Marathon.