Following his military service, he moved to New York, where he made his Broadway debut in Threepenny Opera in 1955. He also occasionally performed sketch comedy back in Chicago with what is now known as Second City. Two years later, he made his onscreen debut in the TV series Studio One and acted continuously on television throughout most of his career.
His breakout role came in 1970, when he made his debut as Lou Grant on the sitcom The Mary Tyler Moore Show, which became a big hit and earned him three Emmys. The show starred Mary Tyler Moore, who died in 2017 at age 80, and Betty White, 99.
Asner reprised his role in a spinoff series, Lou Grant, in 1977, and won two more Emmys for his part. He also won Emmys for roles on Rich Man, Poor Man and the miniseries Roots.
Asner also did a lot of voice acting throughout his career. In the ’90s, he was part of the cast of Batman: The Animated Series, Gargoyles, Spider-Man: The Animated Adventures, Freakazoid! and Captain Planet and the Planeteers, in which he portrayed villain Hoggish Greedly.