Ryoichi Sekiya

is a Japanese ultramarathon and marathon runner from Sagamihara, Kanagawa. He is the current Asian record holder of the 24-hour run with the distance of , which he achieved in 2007 at Soochow International Ultra-Marathon. He is a four-time IAU 24 Hour World Championship winner, which makes him the athlete with the most wins in the event.

Other notable wins of Sekiya include eight wins at the IAU-endorsed Soochow International Ultra-Marathon held in Taipei. He first won the event in 2001, and won in seven consecutive years in 2005, 2007, 2008, 2009, 2010, 2011, and 2012 (there was no event in 2006).

Sekiya won the Spartathlon Ultra Race in Greece in 2002 and 2009.

International competitions