A turbine airfoil comprises a suction sidewall, a pressure sidewall, a tip wall, and a tip leakage control channel. Each sidewall extends spanwise from an airfoil base and chordwise between a leading edge and a trailing edge. The tip wall extends chordwise from the leading edge to the trailing edge and joins respective outer spanwise ends of the suction and pressure sidewalls. The tip leakage control channel has an inlet and an outlet recessed into an outer surface of the tip wall. An inlet of the channel begins proximate a junction of the airfoil pressure sidewall and the tip wall. An outlet of the channel terminates at a recessed portion of the junction of the tip wall and the suction sidewall.