A rotation-locking lighted artificial tree that includes a first and second portion. The first portion includes a trunk, first electrical connector, and first wiring harness. The first electrical connector includes a first body portion and a first electrical contact set. The first body portion includes multiple projections electrically isolated from the first electrical contact set. The second tree portion includes a second electrical connector and a second wiring harness. The second electrical connector includes a second body portion and a second electrical contact set, the second body portion including multiple recesses. When the first tree portion couples to the second, the first and second electrical contact sets form an electrical connection and the recesses of the second body portion receive the projections of the first body portion, thereby electrically connecting and mechanically coupling the first tree portion to the second tree portion.