Clark-Y is the name of a particular aerofoil profile, widely used in general purpose aircraft designs, and much studied in aerodynamics over the years. The profile originated in the 1920s, largely from empirical work. For many applications, the Clark-Y has never been bettered, it gives good overall performance in respect of its Lift-to-drag ratio, and has gentle and relatively benign stall characteristics.

The Douglas DC-3 is one example of the Clark-Y in practice.