Johann Friedrich Karl Keil or Carl Friedrich Keil (26 February 1807 – 5 May 1888) was a conservative German Lutheran Old Testament commentator. He was born at Lauterbach near Oelsnitz, Saxony, and died at Rätz, Saxony.
He is best known for his contributions to the Keil & Delitzsch commentaries, written with Franz Delitzsch.
Keil was a student of Ernst Wilhelm Hengstenberg.
"He was a scholar who went along slowly and deliberately, not fantastic, but all the more reasonable and clear, not witty, but all the more beneficial in doctrine and charm by wonderful, unapproachable theories." (Franz Delitzsch about Keil)