As a seasoned story editor in London, Lantz held prominent positions at 20th Century Fox and Columbia Pictures throughout the 1930s and 1940s.
In the early 1940s, Lantz emigrated to the United States, where he was recruited by Bert Allenberg, a talent agent, to establish a New York office for Berg-Allenberg.
Born in Berlin, Lantz was raised in Hungary, the son of a German screenwriter whose family fled to England in the aftermath of Adolf Hitler's rise to power.
After working for Berg-Allenberg for two years, Lantz joined the Gale Agency, serving as the head of the stage and movie departments for a year.
In 1950, Lantz founded his own agency, which he continued to run until his death. His impressive client list boasted some of the most prominent names in the entertainment industry, including James Baldwin, Lillian Hellman, Carson McCullers, Elizabeth Taylor, Richard Burton, Yul Brynner, Montgomery Clift, Myrna Loy, and Liv Ullmann.
Additionally, Lantz represented photographer Arnold Newman, filmmaker Milos Forman, playwright Peter Shaffer, lyricist Alan Jay Lerner, as well as two Supreme Court justices, William Douglas and Rehnquist.
Lantz eschewed modern technology and formalities, preferring to work without computers, email, and written contracts. He believed that a handshake was sufficient, as he once said, "If someone doesn't like me, I want him to be free to go... slavery was abolished. So blame Abraham Lincoln for my system."
