John Christian Frederick Heyer (July 10, 1793 - November 7, 1873) was the first missionary sent abroad by Lutherans in the United States.
He founded the Guntur Mission in Andhra Pradesh, India.
"Father Heyer" is commemorated as a missionary in the Calendar of Saints of the Lutheran Church on November 7, along with Bartholomaeus Ziegenbalg and Ludwig Ingwer Nommensen.