Fane entered the army in 1807, shortly after the death of his father, another soldier and Member for Lyme, under whose will he inherited £4,000 on coming of age; he no doubt later succeeded to most of his estate, which included personal wealth sworn under £20,000.
Unless it was John Fane II, he voted against condemning the trial of the Methodist missionary John Smith in Demerara, 11 June 1824. He voted for the Irish unlawful societies bill, 25 Feb. 1825, and (as he had on 28 Feb. 1821) against Catholic relief, 1 Mar., 21 Apr., 10 May, and the Irish franchise bill, 26 Apr., 9 May 1825. No trace of parliamentary activity has been found for the following session, though he put in one of his rare appearances at Lyme during the general election of 1826.
Fane, who received army half-pay of £200 and a salary of £320 from his clerkship,
Fane, who was not brought forward for the one remaining seat for Lyme at the general election of 1832, died at St. Omer, France, in March 1833.
