Maitland's promotions were as follows: He was Colonel of the 49th Regiment of Foot from 1768 to 1820, a total of 52 years.
Maitland was made Baronet of Clifton in the County of Midlothian, in the Baronetage of the United Kingdom, on 30 November 1818.
In 1819, Alexander Charles Maitland-Gibson, a younger son of the 1st Baronet, married Susan Ramsay.
Sir Alexander Maitland, 1st Baronet, died on 15 February 1820 and is buried at St Andrew's church, Totteridge, in north London.
A memorial plaque inside the church remembers him and other members of his family.