Heidi Gayle Baker (born August 29, 1959) is a Christian missionary, itinerant speaker, and the CEO of Iris Global, a Christian humanitarian organization. She is the author of several books on Christian spirituality.

She met Rolland Baker, the grandson of missionary H. A. Baker, in 1979. They married six months later in 1980; they left for the mission field two weeks after that. They were ordained as ministers in 1985.

In 1980, the Bakers founded Iris Global, a non-profit Christian ministry dedicated to charitable service and evangelism, particularly in developing nations. In 1995, the Bakers moved to Mozambique in order to begin a new ministry focused on the care of orphaned and abandoned children.

Iris Global negotiated with the Mozambican government to assume financial and administrative responsibility for a former government orphanage in Chihango, near the capital city of Maputo. There were roughly 80 children present.