Charles Poulett Thomson was a merchant in London. In 1826 Thomson was elected to represent Dover in the House of Commons. Thomson was appointed Treasurer of the Navy in 1830.
A supporter of parliamentary reform, Thomson and Mark Philips became Manchester's first Members of Parliament in 1832.
Appointed Governor-General of Canada in 1839, he was was created Lord Sydenham in August 1840. Charles Poulett Thomson died on 19th September 1841.