Alexander Johnston

Alexander Johnston may refer to:
 * Alexander Johnston (1775–1849), British colonial official and orientalist in Ceylon
 * Alexander Johnston (Scottish politician) (1790–1844)
 * Alexander Keith Johnston (1804–1871), Scottish geographer
 * Alexander Robert Johnston (1812–1888), British colonial official
 * Alexander Johnston (artist) (1816–1891), Scottish painter
 * Alexander Keith Johnston (1844–1879), Scottish geographer
 * Alexander Johnston (footballer) (1881–1917), Scottish footballer
 * Alexander Johnston (historian) (died 1889), American historian
 * Alexander Johnston (Canadian politician) (1867–1951), Canadian journalist, civil servant and politician
 * Alexander Johnston (British Army officer) (1884–1952), Hampshire cricketer and army officer
 * Alexander W. Johnston (died 1932), Member of the Legislative Council of Samoa
 * Alex Johnston (Australian rules footballer) (1881–1965), Australian rules footballer
 * Alex Johnston (rugby league) (born 1995), Australian professional rugby league footballer