William Aitken may refer to:
- William McKay Aitken (born 1934), Scottish-born writer and traveller, long a citizen and resident of India
- William Aitken (MP) (1905–1964), journalist and politician
- William Aitken (footballer) (1894–1973), Scottish soccer player
- William Alexander Aitken (1785–1851), fur trader with the Ojibwe
- William Aubrey Aitken (1911–1985), second Bishop of Lynn, 1972–1986
- Bill Aitken (politician) (born 1947), Scottish politician
- William Aitken (pathologist) (1825–1892), Scottish pathologist