Yajima Kajiko (矢嶋 楫子, 1833 – June 16, 1925) was the founder of the Women's Reform Society and president of Japan's Woman's Christian Temperance Union. An educator, pacifist, and Christian activist, she vigorously advanced the cause for the education of women in Japan. Her name was usually seen as Kaji Yajima in the American press of her day.
Yajima worked with Sasaki Toyoju, the secretary of Japan's WCTU. Together they attempted to advocate the reform of feudalistic customs which subjugated Japan to the West and women to men. Yajima in particular advocated for temperance due to her brief marriage to an alcoholic. Both worked towards the elimination of prostitution, as well as the elimination of geisha culture and concubinage. Late in life, Yajima attended international meetings on peace and temperance, and met with American suffragists.