Atsushi Sato (佐藤敦之?, born 8 May 1978) is a Japanese long-distance runner who competes in marathon races. He is the Asian record holder in the half marathon with his time of 60:25 minutes. His marathon best of 2:07:13 hours is the fourth fastest by a Japanese athlete. He is married to Miho Sato (née Sugimori), who was a 2004 Japanese Olympian.
At major championships, he has twice finished in the top ten in the marathon at the World Championships in Athletics, including sixth at the 2009 World Championships marathon. He has also had two top ten finishes at the IAAF World Half Marathon Championships. He represented Japan at the 2008 Beijing Olympics, but was last in the marathon. He also competed for Japan in the 10,000 metres at the 2002 Asian Games.
Sato began running at an early age and represented his junior and senior high schools in Aizuwakamatsu in the 1500 metres and 5000 metres. He entered higher education at Waseda University and began running over longer distance while there. He made his debut in the marathon at the 2000 Lake Biwa Marathon and he came fourth in a time of 2:09:50 hours, which made him the fastest ever Japanese collegiate runner at that time. On his second outing at the 2001 Fukuoka Marathon he was less successful, as he finished out of contention in eleventh place.