Alexander Leith may refer to:
Sir Alexander Leith (British Army officer) (1774–1859) Sir Alexander Leith, 1st Baronet, of Newcastle-upon-Tyne (1869–1956) Sir Alexander Leith, 1st Baronet, of Burgh St Peter (1741–1780), British soldier and politician Alexander Forbes-Leith, 1st Baron Leith of Fyvie (1847–1925) Sir Alexander William Wellesley Leith, 3rd Baronet (1806–1842), of the Leith-Buchanan baronets Sir Alexander Wellesley George Thomas Leith-Buchanan, 5th Baronet (1866–1925), of the Leith-Buchanan baronets