Mao Ichiyama (一山 麻緒, Ichiyama Mao, born 29 May 1997 in Izumi, Kagoshima Prefecture, Japan) is a Japanese long-distance runner.

She represented Japan at the 2020 Tokyo Olympics.

Ichiyama is winner of 2017 Fukuoka International Cross Country (8 km in 26:46) and 2020 Nagoya Women's Marathon in 2:20:29 thus beating 2:21:47 time of Mizuki Matsuda (2020 Osaka International Women's Marathon) to enter as third participant to 2020 Tokyo Olympics, together with Honami Maeda and Ayuko Suzuki.

[2] She won 2021 Osaka Women's Marathon with new event record 2:21:11.

This biographical article relating to Japanese athletics is a stub.