Ernst Gerhard Wilhelm Keyl (22 May 1804 in Leipzig, Germany – 4 August 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 Lutheran Church–Missouri Synod's (LCMS) Eastern District.
He graduated from Leipzig in 1829, and, after holding Lutheran pastorates, emigrated to the United States in 1839, and officiated successively in Missouri, Milwaukee, Baltimore, and Willshire, Ohio. From 1854 to 1869, he was president of the Eastern District of the LCMS, of which he was a founder.
- Lutherophilus (St. Louis, 1854)
- Katechismus-Auslegung aus Dr. Luther's Schriften (4 vols., 1853–68)
- Predigt-Entwürfe über die Sonn und Festtags-Evangelien aus Dr. Luther's Predigten (1866)
His biography was published by J. F. Kostering (St. Louis, 1882).