William Sadler may refer to:
William Sadler (painter) (c. 1782–1839), Irish landscape painter William Sadler (Medal of Honor) (1854–?), American sailor and Medal of Honor recipient William Sadler (actor) (born 1950), American film and television actor William S. Sadler (1875–1969), American surgeon and psychiatrist William Richard Sadler, American politician from Pennsylvania Billy Sadler (born 1981), American baseball pitcher Bubby Sadler (William Andrew Sadler, 1909–1987), American Negro league baseball player Bill Sadler (engineer) (William George Sadler, born 1931), Canadian race car designer, electrical and electronics engineer, aviation designer