Born in Scotland in 1764, he became an army captain at the age of 23 in 1787. In 1789 he was involved in a duel with Frederick, Duke of York, who had accused him of ungentlemanly behaviour. A few months later he was involved in another duel, and later in the year he married Lady Charlotte Gordon, daughter of the 4th Duke of Gordon. In 1794 and 1795 he participated in naval engagements against the French in the West Indies and Gibraltar, but was sent home when he came into conflict with his superiors.
He became the 4th Duke of Richmond on December 29, 1806, after the death of his uncle, Charles Lennox, 3rd Duke of Richmond. In April 1807 he became Lord Lieutenant of Ireland. He remained in that post until 1813, with Arthur Wellesley (the later Duke of Wellington) as his secretary. He participated in the Napoleonic Wars and in 1815 he was in command of a reserve force in Brussels, which was protecting that city in case Napoleon won the Battle of Waterloo. On June 15, the night before the Battle of Quatre Bras, he held a ball for his fellow officers. Although he observed the battle the next day, as well as Waterloo on June 18, he did not participate in either.
In 1818 he was appointed Governor General of Upper Canada. While visiting the territory in 1819, he was bitten by a pet fox, and died of rabies on August 28 of that year. His title was inherited by his son, Charles Gordon-Lennox, 5th Duke of Richmond.
The town of Richmond, Ontario was named for him after his death. According to tradition, the town of Richmond Hill, Ontario was also named for him, as he was said to have passed through the then village during his visit in 1819.
| Preceded by: Charles Lennox | Duke of Richmond and Lennox | Followed by: Charles Lennox |