Charles Thomson Ritchie, 1st Baron Ritchie (1838-1906), was an British politician.

He was born at Dundee, and educated at the City of London School. He went into business, and in 1874 was returned to parliament as Conservative member for the Tower Hamlets. In 1885 he was made secretary to the Admiralty, and from 1886 to 1892 was President of the Local Government Board in Lord Salisbury's second administration, sitting as member for St Georges in the East. He was responsible for the Local Government Act of 1888 , instituting county councils; and a large section of the Conservative party always owed him a grudge for having originated the London County Council.

In Lord Salisbury's later ministries, as member for Croydon (1895-1906), he was President of the Board of Trade (1895-1900) and Home Secretary (1900-1902); and when Sir Michael Hicks-Beach retired in 1902, he became Chancellor of the Exchequer in Mr Balfour's cabinet. Though in his earlier years he had been a fair-trader, he was strongly opposed to Colonial Secretary Joseph Chamberlain's movement for a preferential tariff, and he resigned office in September 1903.

In December 1905 he was created a peer as Baron Ritchie, but he was in ill-health, and he died at Biarritz in January 1906.