Asner was born in Kansas City, Missouri, His Russian-born parents, Lizzie (née Seliger, 1885–January 16, 1967), a housewife; and David Morris Asner(1877–May 19, 1957) ran a second-hand shop. He was raised in an Orthodox Jewish family. Asner attended Wyandotte High School in Kansas City, Kansas, and the University of Chicago in Chicago, Illinois. He worked on the assembly line for General Motors. Asner served with the U.S. Army Signal Corps and appeared in plays that toured Army camps in Europe.
Following his military service, Asner joined the Playwrights Theatre Company in Chicago, but left for New York City before members of that company regrouped as the Compass Players in the mid-1950s. He later made guest appearances with the successor to Compass, The Second City, and is considered part of The Second City extended family. In New York City, Asner played Jonathan Jeremiah Peachum in the Broadway revival of Threepenny Opera, and began to make inroads as a television actor. Before he landed his role with Mary Tyler Moore, Asner guest-starred in such television series as the syndicated crime drama Decoy, starring Beverly Garland, and the NBC western series The Outlaws. He was also cast on Jack Lord's ABC drama series Stoney Burke and in the series finale of CBS's The Reporter, starring Harry Guardino. He also appeared on Mr. Novak, Mission: Impossible,The Invaders. Asner also played a minor character in children's television show W.I.T.C.H. (Napoleon- Cornelia's younger sister's cat). Asner is best known for his character Lou Grant, who was first introduced on The Mary Tyler Moore Show in 1970. In 1977, after the series, Asner's character was given his own show, Lou Grant (1977–82). In contrast to the Mary Tyler Moore show, a thirty-minute comedy, the Lou Grant show was an hour-long award-winning drama about journalism. (For his role as Grant, Asner is the only actor to win an Emmy Award for a sitcom and a drama for the same role.) Other television series starring Asner in regular roles include Thunder Alley, The Bronx Zoo, and Studio 60 on the Sunset Strip. He also portrayed art smuggler August March in an episode of the original Hawaii Five-O (1975) and reprised the role in the Hawaii Five-0 (2012) remake. Asner was acclaimed for his role in the ABC miniseries Roots, as Captain Davies, the morally conflicted captain of the Lord Ligonier, the slave ship that brought Kunta Kinte to America. That role earned Asner an Emmy Award, as did the similarly dark role of Axel Jordache in the mini-series Rich Man, Poor Man (1976). In contrast, he played a former Pontiff in the lead role of Papa Giovanni: Ioannes XXIII (Pope John XXIII 2002), an Italian miniseries for RAI. Asner has also had an extensive voice acting career. He provided the voices for Joshua on Joshua and the Battle of Jericho (1986) for Hanna-Barbera, J. Jonah Jameson on the 1990s animated television series Spider-Man (1994–98); Hoggish Greedly on Captain Planet and the Planeteers (1990–95); Hudson on Gargoyles (1994–96); Jabba the Hutt on the radio version of Star Wars; Master Vrook from Star Wars: Knights of the Old Republic and its sequel; Roland Daggett on Batman: The Animated Series (1992–94); Cosgrove on Freakazoid!; Ed Wuncler on The Boondocks (2005–10); and Granny Goodness in various DC Comics animated series. Asner provided the voice of Carl Fredricksen in the Academy Award-winning Pixar film Up (2009). He received great critical praise for the role, with one critic going so far as to suggest "They should create a new category for this year's Academy Award for Best Vocal Acting in an Animated Film and name Asner as the first recipient." He has appeared in a recurring segment, on The Tonight Show with Jay Leno, entitled "Does This Impress Ed Asner?" He was cast in a Country Music Television comedy pilot, Regular Joe. In 2001, Asner was the recipient of the Screen Cast Guild Life Achievement Award. Asner has won more Emmy Awards for performing than any other male actor (seven, including five for the role of Lou Grant). In 2003, he was inducted into the Academy of Television Arts & Sciences Hall of Fame. In July 2010, Asner completed recording sessions for Shattered Hopes: The True Story of the Amityville Murders; a documentary on the 1974 DeFeo murders in Amityville, New York. Asner served as the narrator for the film, which covers a forensic analysis of the murders, the trial in which 23-year-old DeFeo son Ronald DeFeo Jr., was convicted of the killings, and the subsequent "haunting" story which is revealed to be a hoax. Also in 2010, Asner played the title role in "FDR", a stage production about the life of Franklin Delano Roosevelt he has subsequently continued to tour the play throughout the country. In January 2011, Asner took a supporting role on CMT's first original sitcom Working Class. He made an appearance in the independent comedy feature Not Another B Movie, and had a small but pivotal role as billionaire Warren Buffett in HBO's 2011 economy drama Too Big to Fail. Asner has also provided voice-over narration for many documentaries and films of social activism.
- Asner portrayed Santa Claus in Elf and Uncle Nick in National Lampoon's Christmas Vacation 2.
- Asner also voiced Carl Fredricksen in the Pixar movie, Up.
- He has done a lot of acting works in his early years.