Ernst Gerhard Wilhelm Keyl (May 22, 1804 in Leipzig, Germany – August 4, 1872 in Monroe, Michigan) was a German-born Lutheran clergyman who worked in the United States.

He was a founder and the first president of the Eastern District of the Lutheran Church–Missouri Synod's (LCMS).

Keyl graduated from Leipzig University in 1829 and served as a pastor Niederfrohna, near Penig, beginning in 1829.

He later served as pastor in Frohna, Missouri (1839–1847); Freistadt and Milwaukee, Wisconsin (1847–1850); Baltimore, Maryland (1850–1869); and Willshire, Ohio.

He was a scholar of the life and work of Martin Luther.