Masa Nakayama (中山 マサ, Nakayama Masa, January 19, 1891 – October 11, 1976) was a Japanese politician, who was the first woman appointed to the Cabinet of Japan when she became Minister of Health and Welfare in 1960.
She was born Masa Iida-Powers in Nagasaki, the daughter of Rodney H. Powers, an American businessman, and his Japanese partner, Naka Iida. Masa attended Kwassui Jogakko, a mission school run by American Methodist missionaries. She also studied at Ohio Wesleyan University in the United States, graduating in 1916 and starting a distinguished career in education prior to the outbreak of World War II.
In 1947, she was elected as a member of the House of Representatives in the Diet, representing the second district of Osaka Prefecture for the LDP as part of Hayato Ikeda's government. In 1960, she became the first woman appointed to the Cabinet of Japan when she was made Minister of Health and Welfare. She served as a minister for five months, stepping down in December 1960. Nakayama retired from the Diet in 1969, and was succeeded in her seat by her son, Masaaki.
She was married to Fukuzō Nakayama, who was also a politician and served in the lower house from 1932 to 1942, and later in the upper house. Their sons are Representative Taro Nakayama and Representative Masaaki Nakayama. Representative Yasuhide Nakayama is their grandson and Masaaki's son.
Nakayama died of throat cancer at an Osaka hospital on October 11, 1976, aged 85.