Joseph Martin McCabe (12 November 1867 – 10 January 1955) was an English writer and speaker on freethought, after having been a Roman Catholic priest earlier in his life. He was "one of the great mouthpieces of freethought in England". Becoming a critic of the Catholic Church, McCabe joined groups such as the Rationalist Association and the National Secular Society. He criticized Christianity from a rationalist perspective, but also was involved in the South Place Ethical Society which grew out of dissenting Protestantism and was a precursor of modern secular humanism.