Born as Leo Grattan Carroll on the 25th of October, 1886, in Weedon Bec, Northamptonshire, England, he was an esteemed English actor boasting a career spilling over 40 years. Beginning his voyage in 1912 with stage acting, Carroll's early life was marked with diverse roles in London and on Broadway, taking an interruption only to serve in the British Army during First World War. Tracing his film contributions, he made a debut with Sadie McKee in 1934, identifying heavily with roles of doctors, butlers and authority figures. His portfolio of films ranges from Charlie Chan films and Father of the Bride (1950) to cherished roles in six Alfred Hitchcock films including Rebecca (1940), Suspicion (1941), The Paradine Case (1947), Strangers on a Train (1951) and North by Northwest (1959).

In addition to his wide-reaching film career, Carroll stepped into the realm of television series as well, portraying key roles in Topper, Going My Way, and The Man from U.N.C.L.E. He was also known for roles in We're No Angels (1955), and The Parent Trap (1961). Carroll was one of the first actors to appear in two different television series as the same character. Unfortunately, his journey came to an end on 16th of October, 1972 due to cancer-induced pneumonia. A significant figure in the realm of acting, Carroll's legacy is perpetuated today through his contributions to the film and TV industry.