Sir Alexander Allan, 1st Baronet (c. 1764 – 14 September 1820) was a British painter and politician.

Of obscure origins, he joined the East India Company as a cadet in 1779 and had been promoted to captain when he served in the Fourth Mysore War in 1798 as Deputy Quartermaster-General. He painted numerous water colours of the campaign.^[1]

On his return to England he was elected Member of Parliament (MP) for Berwick-upon-Tweed from 1803 to 1806 and 1807 to 1820.^[2] He was a director of the East India Company from 1814 to 1817 and 1819 to his death.

He was made a baronet on 18 September 1819, of Kingsgate in the County of Kent.^[3] The title became extinct upon his death in 1820. He never married and left a large part of his wealth to Fanny Franklyn, the wife of Henry Franklyn of Copthall House, near Luton, Bedfordshire, with remainder to her son Alexander Allen Franklyn, later Webbe.^[2]