Sir John Salusbury Salusbury-Trelawny, 9th Baronet (2 June 1816 – 4 August 1885), was a British Liberal politician.

Born at Harewood on 2 June 1816 to Patience Christian Carpenter and Sir William Salusbury-Trelawny, the 8th Baronet of Trelawny. He was educated at Westminster School and Trinity College, Cambridge.^[2]

In 1840, Trelawny was appointed Deputy-lieutenant of Cornwall and captain of the Cornwall Rangers; subsequently commanding the 2nd Cornwall Rifles Militia. In 1841 he was called to the bar, but never practiced and, in the same year, unsuccessfully contested Cornwall East Parliament Constituency as a Liberal. Salusbury-Trelawny sat as Member of Parliament for Tavistock between 1843 and 1852 and 1857 and 1865 and for Cornwall East between 1868 and 1874. He succeeded his father to the baronetcy in 1856 and retired from parliament in 1874 owing to "increasing infirmities".^[3]

Trelawny was twice married:

1. Firstly, in 1842, to Harriet Jane Tremayne, author and daughter of John Hearle Tremayne.^[4]
2. Secondly, in 1881, to Harriet Jacqueline Keppel, widow of Edward George Walpole Keppel of Lexham Hall, daughter of Sir Anthony Buller.^[2]

He had issue from his first marriage.^[5]