William Aitken or Bill Aitken may refer to:
- William Aitken (architect) (1889âÂÂ1961), Scottish-American architect
- William Aitken (politician) (1903âÂÂ1964), journalist and politician
- William Alexander Aitken (1785âÂÂ1851), fur trader with the Ojibwe
- William Aubrey Aitken (1911âÂÂ1985), second Bishop of Lynn, 1972âÂÂ1986
- William Aitken (pathologist) (1825âÂÂ1892), Scottish pathologist
- Bill Aitken (politician) (born 1947), Scottish politician
- Bill Aitken (writer) (1934âÂÂ2025), Scottish-born writer and traveller, long a citizen and resident of India
- Billy Aitken (footballer) (1894âÂÂ1973), Scottish football player