Chetwynd-Talbot was the son of Charles Chetwynd-Talbot, 2nd Earl Talbot and Frances Thomasine Lambart. He was educated at Eton College and Sandhurst, and was commissioned an ensign in the 35th (Royal Sussex) Regiment of Foot on 19 December 1836. He purchased a lieutenancy in the 7th Regiment of Foot on 15 September 1837. On 29 March 1842, he purchased a captaincy in the regiment. From 1844 to 1845, he was comptroller of the household to the Lord Lieutenant of Ireland, Lord Heytesbury.
