Ingham featured in over 200 British and American films and TV productions, including Undermind, 'Test for the Future', Episode 9, an ATV ( Associated Television ), production, aired 3/7/'65; also the lead, in "A Challenge for Robin Hood" (1967). After playing Sejanus in Granada TV's "The Caesars" (1968), he had a short spell as an ambitious government minister in "The Power Game" in 1969. In 1971, Ingham took the leading role in the series "Hine", as an unscrupulous arms dealer. Sir John Gielgud gave him his Broadway debut and he subsequently played in many Broadway musicals, including "Copperfield" on Broadway, and opposite Angela Lansbury in the London production of "" in 1973. When the production transferred to Broadway, Ingham did not remain with the show. He was acclaimed for his performance as King Pellinore in the 1981-82 revival of "Camelot" starring Richard Harris. In 1986, he voiced Basil of Baker Street, the lead character of Disney's "The Great Mouse Detective".