Born in Belfast Ireland, to a devout family of Scottish ancestry, Carmichael was educated at home and in England, where she lived with the family of Robert Wilson after her father’s death. While never officially adopted, she used the hyphenated name Wilson-Carmichael as late as 1912. Her missionary call came through contacts with the Keswick movement.
In 1892 she volunteered to the China Inland Mission but was refused on health grounds. However, in 1893 she sailed for Japan as the first Keswick missionary to join the Church Missionary Society (CMS) work led by Barclay Buxton. After less than two years in Japan and Ceylon, she was back in England before the end of 1894. The next year she volunteered to the Church of England Zenana Missionary Society, and in November 1895 she arrived in South India, never to leave. While still learning the difficult Tamil language, she commenced itinerant evangelism with a band of Indian Christian women, guided by the CMS missionary Thomas Walker. She soon found herself responsible for Indian women converts, and in 1901, she, the Walkers, and their Indian colleagues settled in Dohnavur.
During her village iterations, she had become increasingly aware of the fact that many Indian children were dedicated to the gods by their parents or guardians, became Temple children, and lived in moral and spiritual danger. It became her mission to rescue and raise these children, and so the Dohnavur Fellowship came into being (registered 1927).
Known at Dohnavur as Amma (Mother), Carmichael was the leader, and the work became well known through her writing. Workers volunteered and financial support was received, though money was never solicited. In 1931 she had a serious fall, and this, with arthritis, kept her an invalid for the rest of her life. She continued to write, and identified leaders, missionary and Indian, to take her place. The Dohnavur Fellowship still continues today.