IMDB entry:

One of the most indispensable of character actors, Leo G. Carroll was already involved in the business of acting as a schoolboy in Gilbert & Sullivan productions. Aged 16, he portrayed an old man in ‘Liberty Hall’. In spite of the fact, that he came from a military family, and , perhaps, because of his experience during World War I, he decided against a military career in order to pursue his love of the theatre. In 1911, he had been a stage manager/actor in ‘Rutherford and Son’ and the following year took this play to America. Twelve years later, Leo took up permanent residence in the United States. His first performance on Broadway was in ‘Havoc’ (1924) with Claud Allister, followed by Noel Coward‘s ‘The Vortex’ (1925, as Paunceford Quentin). Among his subsequent successes on the stage were ‘The Green Bay Tree’ (1933) as Laurence Olivier‘s manservant, ‘Angel Street’ (aka ‘Gaslight’,1941) as Inspector Rough, and the ‘The Late George Apley’ (title role). The latter, a satire on Boston society, opened in November 1944 and closed almost exactly a year later. A reviewer for the New York times, Lewis Nichols, wrote “His performance is a wonderful one. The part of Apley easily could become caricature but Mr.Carroll will have none of that. He plays the role honestly and softly.” The play was filmed in 1947, with Ronald Colman in the lead role. Leo’s film career began in 1934. He was cast, to begin with, in smallish parts. Sometimes they were prestige ‘A pictures’, usually period dramas, such as The Barretts of Wimpole Street (1934) and Wuthering Heights (1939).

Leo was a consummate method actor who truly ‘lived’ the parts he played, and, as a prominent member of Hollywood’s British colony, attracted the attention of Alfred Hitchcock. Indeed, the famous director liked him so much, that he preferred him to any American actor to play the part of a U.S. senator in Strangers on a Train (1951). A scene stealer even in supporting roles, Leo G. Carroll lent a measure of ‘gravitas’ to most of his performances, point in case that of the homicidal Dr. Murchison in Spellbound (1945) (relatively little screen time, but much impact !) and the professor in North by Northwest(1959). On the small screen, Leo lent his dignified, urbane presence and dry wit to the characters of Cosmo Topper and Alexander Waverly, spymaster and boss of Napoleon Solo and Ilya Kuryakin in The Man from U.N.C.L.E. (1964), the part for which he is chiefly remembered.

Leo G. Carroll appeared in over 300 plays during his career and the stage remained his preferred medium. He once remarked “It’s brought me much pleasure of the mind and heart. I owe the theatre a great deal. It owes me nothing” (NY Times, October 19,1972).

– IMDb Mini Biography By: I.S.Mowis

The above IMDB entry can also be accessed online here.