Saeko Okayama (岡山 沙英子, Okayama Saeko, born 12 April 1982 in Hiroshima Prefecture) is a Japanese long jumper. She holds a personal best jump of 6.59 metres. She was a bronze medalist at the 2011 Asian Championships and a three-time national champion at the Japanese Championships. Her mother Emiko Koumaru is also a former Long jumper, having competed at the 1964 Summer Olympics in Tokyo. She was also the 1966 Japanese Championships champion and former Japanese record holder.