Michael Rennie

Rennie worked as a car salesman and in the textile industry before turning to acting in his mid-twenties, gradually building a solid but unspectacular career in British film through the 1930s and 40s.

He was cast as Klaatu specifically because American audiences wouldn't recognize him — the studio wanted an alien visitor who felt like a genuine stranger, not a movie star. A working British actor with a respectable but unspectacular career up to that point, he was deliberately chosen over more famous American actors.

The role became by far the most enduring of his career, and he continued working steadily in British and American film and television for decades, though never again in a part as culturally significant.