Captain William Younghusband took command of Alexander for her fourth voyage, this one to Bombay and Madras. His letter of marque was dated 30 January 1810. He left Portsmouth on 14 March 1810 and arrived at Bombay on 2 July. From there he sailed to Madras, where he arrived on 25 August. From Madras Alexander sailed to Rodrigues, in the Mascarene Islands. Next, she visited Mauritius, arriving on 29 December. She then sailed to Acheh, arriving there on 27 July 1811, before returning to Madras on 14 March. By 13 July Alexander was at the Cape of Good Hope. A little over a month later she was at St Helena (19 August), and by 21 November she was back at Blackwall Yard.
