Derek is the English form of the Dutch Diederik, which goes back to the Germanic Theodoric and means "ruler of the people", from theud, people, and ric, ruler. The name came to England with Flemish traders in the Middle Ages and had its American heyday in the 1970s and 1980s. Derek stood at number 121 in 2000, its best rank this century, slipped to 211 in 2015 and ranks 284th among boys' names in 2025.