Charles John Barnett (12 March 1790 – 4 August 1856) was an officer in the British Army who also served as a diplomat. He served in the 3rd Regiment of Foot. He reached the rank of captain in 1812 and lieutenant colonel in 1821. He took part in the Battle of Waterloo in 1815, and retired from the military in 1830. He was appointed Consul in Warsaw, Poland on 31 May 1833. He was later appointed Consul-General in Egypt on 11 May 1841, which post he held till 17 August 1846, when he retired. He died on 4 August 1856 in Englefield Green, Surrey.