[1] In a career of more than 40 years, he appeared in six Hitchcock films including Spellbound, Strangers on a Train and North by Northwest and in three television series, Topper, Going My Way, and The Man from U.N.C.L.E.

During 1933–34, Carroll had the role of "impeccable valet"[3] Trump in the Broadway play The Green Bay Tree[4] (which has no relation to the novel by Louis Bromfield apart from the shared title), and in 1941 starred with Vincent Price and Judith Evelyn in Patrick Hamilton's Angel Street (better known as Gaslight), which ran for three years at the Golden Theatre on West 45th Street in New York City.

In the 1951 film The Desert Fox: The Story of Rommel he played a sympathetic German field marshal, Gerd von Rundstedt, presenting him as a tragic, resigned figure completely disillusioned with Hitler.

Carroll is perhaps best known for his roles in six Alfred Hitchcock films: Rebecca (1940), Suspicion (1941), Spellbound (1945), The Paradine Case (1947), Strangers on a Train (1951) and North by Northwest (1959).

Carroll had a central role in the highly rated movie We're No Angels (1955) with Humphrey Bogart, Peter Ustinov and Basil Rathbone, among others.

Mosby with actress Hayley Mills in The Parent Trap (1961), Carroll is remembered for his role as the frustrated banker haunted by the ghosts of George and Marion Kerby in the television series Topper (1953–1956), with co-stars Anne Jeffreys, Robert Sterling and Lee Patrick.

[5]: 1097–1098  He appeared as the older Father Fitzgibbon from 1962 to 1963 in ABC's Going My Way, a series about two Roman Catholic priests at St. Dominic's parish in New York City.

[6] Carroll was posthumously referenced in the lyrics of "Science Fiction/Double Feature", the opening song of the musical stage production The Rocky Horror Show and its 1975 film adaptation.