In addition to his radio shows, Kasem provided the voice of many commercials, performed many voices for Sesame Street, provided the character voice of Peter Cottontail in the Rankin/Bass production of Here Comes Peter Cottontail, was "the voice of NBC", and helped out with the annual Jerry Lewis telethon. He provided the cartoon voices of Robin in "The Adventures of Batman and Robin" and Super Friends, Mark on Battle of the Planets, and a number of characters for the Transformers cartoon series of the 1980s. In 2008, he was the voice of Out of Sight Retro Night which aired on WGN America but was replaced by rival Rick Dees. After 40 years, Kasem retired from his role of voicing Shaggy in 2009, although he did voice Shaggy's father in the 2010 TV series Scooby-Doo! Mystery Incorporated.
Kasem was born in Detroit, Michigan, on April 27, 1932, to Lebanese Druze immigrant parents, who had settled in Michigan, where they worked as grocers. Kasem was named after Turkish leader Mustafa Kemal Atatürk, a man Kasem said his father respected.
In the 1940s, "Make Believe Ballroom" reportedly inspired Kasem to follow a career in radio and later host a national radio hits countdown show. Kasem received his first experience in radio covering sports at Northwestern High School in Detroit. He then went to Wayne State University for college. While at Wayne State, he voiced children on radio programs such as The Lone Ranger and Challenge of the Yukon. In 1952, Kasem was drafted into the U.S. Army and sent to Korea. There, he worked as a DJ/announcer on the Armed Forces Radio Korea Network.
After the war, Kasem began his professional broadcasting career in Flint, Michigan. From there, he spent time in Detroit as a disc jockey for radio station WJBK-AM (and doing such shows as The Lone Ranger and Sergeant Preston of the Yukon); WYSL in Buffalo, New York; and a station in Cleveland before moving to California. At KYA in San Francisco, the general manager first suggested he tone down his 'platter patter' and talk about the records instead. Kasem demurred at first, because it was not what was normally expected in the industry. At KEWB in Oakland, California, Kasem was both the music director and on-air personality. He created a show which mixed in biographical tidbits about the artists' records he played, and attracted the attention of Bill Gavin who tried to recruit him as a partner. After Kasem joined KRLA in Los Angeles in 1963, his career really started to blossom and he championed the R&B music of East L.A.
Kasem earned roles in a number of low-budget movies and acted on radio dramas. While hosting "dance hops" on local television, he attracted the attention of Dick Clark who as a producer hired him to co-host a daily teenage music show called Shebang starting in 1964. Kasem appeared in network TV series including Hawaii Five-O and Ironside. In 1967, Kasem appeared on The Dating Game, and played the role of "Mouth" in the motorcycle gang film The Glory Stompers. In 1969, he played the role of "Knife" in the "surfers vs. bikers" film Wild Wheels, and had a small role in another biker movie, The Cycle Savages, starring Bruce Dern and Melody Patterson.
Kasem's voice was, however, always the key to his career. At the end of the 1960s, he began working as a voice actor. In 1969, he started one of his most famous roles, the voice of Shaggy on Scooby-Doo, Where Are You!. He also voiced the drummer Groove from The Cattanooga Cats that year. In 1964, Kasem had a minor hit single called "Letter From Elaina". A spoken-word recording, it told the story of a girl who met George Harrison after a San Francisco concert.
On July 4, 1970, Kasem, along with Don Bustany, Tom Rounds, and Ron Jacobs, launched the weekly radio program American Top 40 (AT40). At the time, top 40 radio was on the decline as DJs preferred to play album-oriented progressive rock. Loosely based on the TV program Your Hit Parade, the show counted down from #40 on the pop charts to #1—the first #1 was Three Dog Night's "Mama Told Me (Not to Come)"—based on the Billboard Hot 100 each week. The show, however, was not just about the countdown. Kasem mixed in biographical information about the artists, flashback, and "long-distance dedication" segments where he read letters written by listeners to dedicate songs of their choice to far away loved ones. He often included trivia facts about songs he played and artists whose work he showcased. Frequently, he mentioned a trivia fact about an unnamed singer before a commercial break, then provided the name of the singer after returning from the break. Kasem ended the program with his signature sign-off, "Keep your feet on the ground and keep reaching for the stars."
The show debuted on seven stations, but on the back of Kasem's "always friendly and upbeat" baritone voice it soon went nationwide. In October 1978, the show expanded from three hours a week to four. American Top 40's success spawned several imitators including a weekly half-hour music video television show, America's Top 10, hosted by Kasem himself. "When we first went on the air, I thought we would be around for at least 20 years," he later remarked. "I knew the formula worked. I knew people tuned in to find out what the No. 1 record was." Due to his great knowledge of music, Kasem became known as not just a disc jockey, but also a music historian.
In 1971, Kasem provided the character voice of Peter Cottontail in the Rankin/Bass production of Here Comes Peter Cottontail. In the same year, he appeared in the low-budget film The Incredible 2-Headed Transplant, in what was probably his best remembered acting role. From 1973 until 1985, he voiced Robin on several SuperFriends franchise shows. In 1980, he voiced Merry in The Return of the King. He also voiced Alexander Cabot III on Josie and the Pussycats and Josie and the Pussycats in Outer Space, and supplied a number of voices for Sesame Street.
In the late 1970s, Kasem portrayed an actor who imitated Columbo in the Hardy Boys/Nancy Drew Mysteries two-part episode "The Mystery of the Hollywood Phantom." He portrayed a golf commentator in an episode of Charlie's Angels titled "Winning is for Losers", and appeared on Police Story, Quincy, M.E., and Switch. In 1977 he was initially hired as the narrator for the ABC sitcom Soap, but quit after the pilot episode due to the content. Rod Roddy took his place on the program. In 1984, Kasem made a cameo in Ghostbusters, reprising his role as the host of American Top 40. For a period in the late 1970s, Kasem was also the staff announcer for the NBC television network.
In 1988, Kasem left American Top 40 due to a contract dispute with ABC Radio Network. He signed a five-year, $15 million contract with Westwood One and started Casey's Top 40 which used a different chart - the Radio & Records Contemporary (CHR)/Pop radio airplay chart (making it feature exactly the same song positions as the Rick Dees Weekly Top 40, which used the same chart at the time), to determine the top 40. He also hosted two shorter versions of the show: Casey's Hot 20 and Casey's Countdown. During the late 1990s, Kasem hosted the Radio Hall of Fame induction ceremony.
Kasem voiced Mark in Battle of the Planets and several Transformers characters: Bluestreak, Cliffjumper, Teletraan I and Dr. Arkeville. He left Transformers during the third season due to what he perceived as offensive caricatures of Arabs and Arab countries. In a 1990 article, he explained:
A few years ago, I was doing one of the voices in the TV cartoon series, Transformers. One week, the script featured an evil character named Abdul, King of Carbombya. He was like all the other cartoon Arabs. I asked the director, 'Are there any good Arabs in this script for balance?' We looked. There was one other — but he was no different than Abdul. So, I told the show’s director that, in good conscience, I couldn't be a part of that show.
From 1989 to 1998, Kasem hosted Nick at Nite's New Year's Eve countdown of the top reruns of the year. He also made cameo appearances on Saved by the Bell and ALF in the early 1990s. In 1997, Kasem quit his role as Shaggy in a dispute over a Burger King commercial, with Billy West and Scott Innes taking over the character in the late 1990s and early 2000s.
The original American Top 40, hosted by Shadoe Stevens after Kasem's departure, was cancelled in 1995. Kasem regained the rights to the name in 1997, and the show was back on the air in 1998, on the AMFM Network (later acquired by Premiere Radio Networks).
At the end of 2003, Kasem announced he would be leaving AT40 once his contract expired the following month and would be replaced by Ryan Seacrest. He agreed to a new contract to continue hosting his weekly adult contemporary countdown shows in the interim, which at the time were both titled American Top 20. In 2005 Kasem renewed his deal with Premiere Radio Networks to continue hosting his shows, one of which had been reduced to ten songs and had, appropriately, been retitled American Top 10 to reflect the change.
In April 2005, a television special called American Top 40 Live aired on the Fox network, hosted by Seacrest, with Kasem appearing on the show. In 2008, Kasem did the voice-over for WGN America's Out of Sight Retro Night. He was also the host of the short-lived American version of 100% during the 1998–99 season.
In June 2009, Premiere announced it would no longer produce Kasem's two remaining countdowns and end their eleven-year relationship. Kasem decided not to try to bring his show to another syndicator or find a replacement host to continue the show and, citing a desire to explore other avenues in his life such as writing a memoir, the 77-year old Kasem sent out a press release during the last week of June that he would be retiring from radio on July 4 weekend, the thirty-ninth anniversary of the first ever countdown he presided over.
Kasem also performed TV commercial voice-overs throughout his career, appearing in more than 100 commercials in all.
In 2002, Kasem reprised the role of Shaggy when it was determined the character would be a vegetarian. In 2009, he retired from voice acting, with his final performance being the voice of Shaggy in Scooby-Doo! and the Samurai Sword. He did voice Shaggy again for "The Official BBC Children in Need Medley", but went uncredited by his request. Although officially retired from acting, he provided the voice of Colton Rogers, Shaggy's father, on a recurring basis for the 2010–2013 series Scooby-Doo! Mystery Incorporated, again uncredited at his request.
As for his recognizable voice quality, "It's a natural quality of huskiness in the midrange of my voice that I call 'garbage,'" he stated to The New York Times. "It's not a clear-toned announcer's voice. It's more like the voice of the guy next door."
Kasem was a devout vegan, supported animal rights and environmental causes, and was a critic of factory farming. He initially quit voicing Shaggy in the late 1990s, when asked to voice Shaggy in a Burger King commercial, returning in 2002 after negotiating to have Shaggy become a vegetarian.
Kasem was active in politics for years, supporting Lebanese-American and Arab-American causes, an interest which was triggered by the 1982 Israeli invasion of Lebanon. He wrote a brochure published by the Arab American Institute entitled "Arab-Americans: Making a Difference". He turned down a position in season three of Transformers because of the show's plot portraying "evil Arabs". He also called for a fairer depiction of heroes and villains, on behalf of all cultures, in Disney's 1994 sequel to Aladdin called The Return of Jafar. In 1996, he was honored as "Man of the Year" by the American Druze Society. Kasem campaigned against the Gulf War, advocating non-military means of pressuring Saddam Hussein into withdrawing from Kuwait, was an advocate of Palestinian independence and arranged conflict resolution workshops for Arab Americans and Jewish Americans.
A political liberal, he narrated a campaign ad for George McGovern's 1972 presidential campaign, hosted fundraisers for Jesse Jackson's presidential campaigns in 1984 and 1988, supported Ralph Nader for U.S. President in 2000, and supported progressive Democrat Dennis Kucinich in his 2004 and 2008 presidential campaigns. Kasem supported a number of other progressive causes, including affordable housing and the rights of the homeless.
Kasem was married to Linda Myers from 1972 to 1979; they had three children: Mike, Julie, and Kerri Kasem.
Kasem was married to actress Jean Thompson from 1980 until his death. They had one child, Liberty Jean Kasem.
In 1989, Kasem purchased a home built in 1954 and located at 138 North Mapleton Drive, previously owned by developer Abraham M. Lurie, as a birthday present for his wife Jean. In 2013, he listed it for US$43 million.
In October 2013, Kerri Kasem said her father was suffering from Parkinson's disease, which a doctor had diagnosed in 2007; a few months later, she said he was diagnosed with Lewy body dementia, which is often difficult to differentiate from Parkinson's. Due to his condition, he was no longer able to speak during his final months.
As his health worsened in 2013, Jean Kasem prevented any contact with her husband, particularly from his children by his first marriage. On October 1, Kerri, Mike and Julie protested in front of the Kasem home, having not been allowed contact with their father for three months; some of Casey Kasem's long-time friends and colleagues, along with his brother Mouner, also joined the demonstration. The eldest Kasem children sought conservatorship over their father's care, with Julie and her husband Jamil Aboulhosn filing the papers; the court denied their petition in November.
Kasem was removed from a Santa Monica, California nursing home by his wife on May 7, 2014. On May 12, Kerri Kasem was granted temporary conservatorship over her father, despite her stepmother's objection. The court also ordered an investigation into Casey Kasem's whereabouts, after his wife's attorney told the court Casey was "no longer in the United States". He was found soon afterward in Washington state.
On June 6, 2014, Kasem was reported to be in critical but stable condition at a hospital in Washington state, receiving antibiotics for bedsores and treatment for high blood pressure. It was revealed that he had been bedridden for some time. A judge ordered separate visitation times due to antagonism between Jean Kasem and his children from his first wife. Judge Daniel S. Murphy ruled that Kasem had to be hydrated, fed, and medicated as a court-appointed lawyer reported on his health status. Jean Kasem claimed that he had been given no food, water, or medication the previous weekend. Kerri Kasem's lawyer stated that she had him removed from artificial food and water on the orders of a doctor and in accordance with a directive her father signed in 2007 saying he would not want to be kept alive if it "would result in a mere biological existence, devoid of cognitive function, with no reasonable hope for normal functioning." Murphy reversed his order the following Monday, after it became known that Kasem's body was no longer responding to the artificial nutrition, allowing the family to place Kasem on "end-of-life" measures over the objections of Jean Kasem.
On June 15, 2014, Kasem died at St. Anthony's Hospital in Gig Harbor, Washington at the age of 82. The immediate cause of death was reported as sepsis caused by an ulcerated bedsore. He was survived by his wife, four children, and four grandchildren. His body was handed over to his widow, who would make funeral arrangements. Reportedly, Kasem wanted to be buried at Forest Lawn Memorial Park in Glendale.
By July 19, a judge had granted Kasem's daughter Kerri a temporary restraining order to prevent his wife from cremating Kasem's body to allow an autopsy to be performed, but when she went to give a copy of the order to the funeral home, she was informed the body had been moved at the directive of Jean Kasem. Kasem's wife had the body moved to a funeral home in Montreal on July 14, 2014. On August 14, it was reported in the Norwegian newspaper Verdens Gang that Kasem was going to be buried in Oslo.
Kasem's family had his interment at Oslo Western Civil Cemetery on December 16, 2014, more than six months after his death.
In November 2015, three of Kasem's children and his brother sued his widow for wrongful death. The lawsuit charges Jean Kasem with elder abuse and inflicting emotional distress on the children by restricting access prior to his death.
In 1981, Kasem was granted a star on the Hollywood Walk of Fame. He was inducted into the National Association of Broadcasters Hall of Fame radio division in 1985, and the National Radio Hall of Fame in 1992. Five years later, he received the Radio Hall of Fame's first Lifetime Achievement Award. In 2003, Kasem was given the Radio Icon award at the Radio Music Awards.