Michael S. Heiser is an American biblical Old Testament scholar and Christian author. His area of expertise is the nature of the spiritual realm in the Bible, namely the Divine Council and hierarchy of the spiritual order. He is Executive Director of the School of Ministry at Celebration Church in Jacksonville, Florida. He was a Distance learning professor at Liberty University and Midwestern Baptist Theological Seminary. Until 2019, he was scholar-in-residence at Faithlife Corporation.

He runs his own podcast, The Naked Bible and runs a ministry called Miqlat, dedicated to the production and dissemination of his content. Heiser appeared in the 2018 documentary film Fragments of Truth and in the 2019 documentary film The Unseen Realm. In 2019 Heiser released the book The World Turned Upside Down: Finding the Gospel in Stranger Things, referencing the Netflix series Stranger Things as analogies to Christian theology.