Born in New York City, Reed attended Washington High School (now George Washington Educational Campus) and majored in journalism at Columbia University.
Between graduating from WHS and entering Columbia, he studied drama at the American Academy of Dramatic Arts. He began his acting career in the city, eventually working on Broadway. He was Jewish.
For several years, Reed toured in vaudeville with his cousin, Harry Green. He also had two other jobs—operating a wholesale candy factory and working at the Copake Country Club as "social director, entertainment producer and actor."
For a time, he continued to list himself either as Bergman or Alan Reed, depending on the role he was playing (Reed for more comedic roles, Bergman for more serious ones). He was able to act in 22 foreign dialects, and made a career as a successful radio announcer and stage actor.
As early as 1930, Reed (billed as Teddy Bergman) co-starred with Herbert Polesie in Henry and George, a CBS program that featured "minute dramas, popular laughmakers ... interspersed with dance music selections."
Reed's radio work included having two roles in Valiant Lady, the role of Solomon Levy on Abie's Irish Rose, as the "Allen's Alley" resident poet Falstaff Openshaw on Fred Allen's NBC radio show, and later on his own five-minute show, Falstaff's Fables, on ABC, as Officer Clancey and other occasional roles on the NBC radio show Duffy's Tavern, as Shrevey the driver on several years of The Shadow, as Chester Riley's boss on the NBC radio show The Life of Riley, as Italian immigrant Pasquale in Life with Luigi on CBS radio, various supporting roles on Yours Truly, Johnny Dollar, also on CBS, and as Lt. Walter Levinson in several episodes of Richard Diamond, Private Detective.
Reed was "heard regularly on the Crime Doctor series," and "was the original Daddy to Fanny Brice on Baby Snooks." Billed as Teddy Bergman, he had the title role on Joe Palooka.
Billed as Teddy Bergman, Reed appeared on Broadway in Double Dummy (1936), and A House in the Country (1937), and Love's Old Sweet Song (1940).
From 1957–58, Reed appeared in a recurring role as J.B. Hafter, a studio boss, on the CBS sitcom Mr. Adams and Eve, starring Howard Duff and Ida Lupino, then married in real life, but appearing as a fictitious acting couple living in Beverly Hills, California. In 1963, he appeared as Councilman Jack Gramby in episode 8 of the CBS sitcom My Favorite Martian. In 1964–65, he had a recurring role as Mr. Swidler in the ABC sitcom Mickey, starring Mickey Rooney as the owner of a resort hotel in Newport Beach, California.
As a voice actor, Reed provided the voice of Boris the Russian Wolfhound in Walt Disney's Lady and the Tramp in 1955. In 1960, he began the voice role for which he was most famous, that of Fred Flintstone, the lead character of Hanna-Barbera's prime-time animated series The Flintstones. Reed provided Fred's voice for the entire six-season run of the show, as well as in several spin-off series (The Pebbles and Bamm-Bamm Show, The Flintstone Comedy Hour) and specials. His final performance as Fred Flintstone was a cameo guest role on an episode of Scooby's All-Star Laff-A-Lympics. Among his other voice roles for Hanna-Barbera was Touché Turtle's sidekick, Dum Dum.
Radio playwright and director Norman Corwin cast Reed as Santa Claus in the 1969 KCET television reading of his 1938 play The Plot to Overthrow Christmas.
In May 1932, Reed married the former Finette Walker (1909–2005), a Broadway actress whom he met at television station W2XAB (later WCBS-TV) in New York City. She appeared on stage in the early 1930s and was a chorus member in the original 1934 Broadway production of Anything Goes with Ethel Merman. They had three sons, including actor Alan Reed, Jr. (born May 10, 1936). Once his son started acting, Reed took the professional name Alan Reed, Sr.
A decade before his death, Reed, a heavy smoker, was diagnosed with bladder cancer which was surgically removed. Although this operation was successful, he later developed emphysema and died of a heart attack two months before his 70th birthday. His body was donated to medical research.Porky's Romance (1937) (Looney Tunes Short) as Opening Announcer (uncredited/unconfirmed)
Days of Glory (1944) as Sasha
Nob Hill (1945) as Dapper Jack Harrigan
The Postman Always Rings Twice (1946) as Ezra Liam Kennedy
Viva Zapata! (1952) as Pancho Villa
Lady and the Tramp (1955) as Boris
Time Table (1956) as Al Wolfe
Breakfast at Tiffany's (1961) as Sally Tomato
The Man Called Flintstone (1966) as Fred Flintstone
Shinbone Alley (1971) as Big Bill
Energy: A National Issue (1977) as Fred Flintstone
The Story of Heidi (1979) as Sebastian and Mr. Usher
Low resolution experimental programming - W2XAB, CBS, New York (early 1930s)
Make Room for Daddy - episode - "The Reunion" - Joe Ferbus (1958)
Have Gun - Will Travel - episode - "Gold and Brimstone Dirks" (1959)
Peter Gunn - episode - "The Maître d'" - Garson (1960)
Make Room for Daddy - episode - "The Apple Polishers" - Howard Sloan (1960)
The Flintstones - 166 episodes - Fred Flintstone/Professor Von Messerschmidt/J.L. Gothrocks/The Prowler/Grandpa Rocky Flintstone (1960–1966)
The Hanna-Barbera New Cartoon Series - Segment - Touché Turtle and Dum Dum - 50 Segments - Dum Dum (1962)
The Dick Van Dyke Show - episode - "The Masterpiece" - Auctioneer (1963)
The Beverly Hillbillies - episodes - "Teenage Idol" - Eddie Colton (1964) and "The Great Tag-Team Match" - Gene Booth (1968)
Hoppity Hooper (1964)
Space Ghost - Glasstor (1966)
Alice in Wonderland (or What's a Nice Kid Like You Doing in a Place Like This?) - TV Special - The Talking Caterpillar & Fred Flintstone (1966)
Batman - episode - "Penguin Sets a Trend" - General MacGruder (1967)
Petticoat Junction - episode - "Bad Day at Shady Rest" - the Bandit (alias Mr. Lawson) (1968)
Get Smart - episode - "Valerie of the Dolls" - Little girl (voice, uncredited) (1969)
Where's Huddles? - 10 episodes - Mad Dog Mahoney (1970)
The Pebbles and Bamm-Bamm Show - Fred Flintstone (1971)
The Flintstone Comedy Hour - Fred Flintstone (1972)
Laff-A-Lympics - episode - "The Swiss Alps and Tokyo", Japan - Fred Flintstone (1977)
Captain Caveman and the Teen Angels (1977)