Tregenna is a surname of Cornish origin. Recorded variations include Treganna, Tregona, Tregannah, Tregunna, Tregensoe, Tregensowe, Tregenza, and Tregenzo. The name is believed to have originated in the phrase tre-cenue (also tre-gonyow or tre-kensa), meaning the first or foremost farm or homestead on the downs. Examples from the church registers of Cornwall date to at least as early as 1547. The name Tregenna may refer specifically to: