Berthold III, Duke of Zähringen (b. c. 1085, d. 3 December[1] 1122) was Duke of Zähringen from 1111 until his death.He was the son of Berthold II (c. 1050–1111), the first holder of the ducal title.
Berthold III was a supporter of emperor Henry V and was significantly involved in the Concordat of Worms of 1122.He was married to Sophia of Bavaria, a daughter of Henry IX, Duke of Bavaria.He was killed on 3 December 1122 near Molsheim in the course of a feud, and was buried at St. Peter Abbey.
He died without male issue, and was succeeded by his brother, Conrad I(c. 1090–1152).