William Smythe may refer to:
W. E. Smythe (William Ellsworth Smythe, 1861–1922), journalist, writer and founder of the Little Landers movement William Smythe (physicist) (1893–1988), American physicist and mentor of six Nobel Prize laureates William James Smythe (1816–1887), general and colonel-commandant of the Royal Artillery William Smythe (academic), Oxford college head Harry Smythe (William Henry Smythe, 1904–1980), pitcher in Major League Baseball William Smythe of the Smythe baronets William Smythe (geophysicist) and namesake of Smythe Shoulder
See also William Smyth (disambiguation) William Smith (disambiguation)