Theodore Herzl Ainley (3 October 1903 – 19 March 1968) was a British trade union leader and communist activist.
Born Theodore Abrahamson in Cheetham, in Manchester, he was educated at a Jewish school, leaving when he was thirteen, to undertake an apprenticeship as a chemist.
Ted joined the Communist Party of Great Britain the following year, and also began working full-time for the YCL, as its organiser for North East England and Glasgow.
He was elected to the National Executive of Committee of the YCL, and in 1929, attended the Lenin School in Moscow.
He won election as the union's general secretary in 1949, but took early retirement in 1951 due to poor health.