Kiyoko Shimahara (嶋原 清子, born 22 December 1976) is a Japanese long-distance runner who competes in marathon races.

Born in the Ōshima District in Yamaguchi Prefecture, she attended Kokushikan University and graduated in 1999 with a degree in physical education.

[4] She came third at the Tokyo Marathon in 2003, then improved to second place behind Bruna Genovese at the same competition the following year, setting a personal best of 2:26:43 hours in the process.

[5] She gained her first international call-up for Japan at the 2006 Asian Games and she was the marathon silver medallist behind China's Zhou Chunxiu.

[7] At the 2007 London Marathon, she withdrew mid-race for the first time, pulling up just after the halfway point due to breathing difficulties.