Hawk of the Wilderness (1938) is a Republic movie serial based on the Kioga adventure novels written by pulp writer William L. Chester (1907–1971). Kioga was a Tarzanesque white child raised on a lost island in the Arctic Circle, somewhere in northern Siberia, which was heated by thermal springs and unknown currents. Chester wrote four Kioga novels. The first, Hawk of the Wilderness (1935), was the one that was filmed as the 12-part 1938 Republic serial. (The other novels in the series were Kioga of the Wilderness (1936), One Against a Wilderness (1937) and Kioga of the Unknown Land (1938).

Herman Brix had earlier also played Tarzan on film in the 1935 Edgar Rice Burroughs-produced serial The New Adventures of Tarzan. Hawk of the Wilderness was later re-edited into a feature film version for television as The Lost Island of Kioga in 1966.