Lewis is thought to have been born April 30, 1923. Few other facts about Lewis are known with any certainty; most of the information comes from interviews he gave, but there are inconsistencies in his statements. Sometimes he gave his birth year as 1910; other times, 1923. Ted Lewis, his son, said his father was born in 1923. Dan Barry of The New York Times wrote in reference to Lewis: "Actors who lie about their age usually subtract, not add, years, and few would have the nerve to fudge those years by more than a decade.
Lewis was born under the name Albert Meister or possibly Alexander Meister to a Jewish family in Brooklyn, New York. Other sources place his birth in Wolcott, New York, but no official record of his birth has been published to date, and officials in Wolcott say they have no record of any Meister.
The Times wrote: "Lewis was born Albert Meister, probably in 1923, although he insisted that he was born in 1910. This, and Lewis's many other questionable stories, means that much of the actor's life is a broth of conjecture that his fans will no doubt squabble over for years to come." On his application for a Social Security number, completed sometime between 1936 and 1950, Lewis gave a date of birth of April 30, 1923. As to why Lewis might have lied about his age, the most common theory is that in 1964 he might have been concerned about being a year younger than Yvonne De Carlo, who was cast to play his daughter, Lily Munster.
In a 1998 interview with Walt Shepperd, Al Lewis said:
My mother was a worker, worked in the garment trades. My mother was an indomitable spirit. My grandfather had no sons. He had six daughters. They lived in Poland or Russia, every five years it would change. My mother being the oldest daughter, they saved their money, and when she was about sixteen they sent her to the United States, not knowing a word of English. She went to work in the garment center, worked her back and rear-end off and brought over to the United States her five sisters and two parents. I remember going on picket lines with my mother. My mother wouldn't back down to anyone.
Lewis said he moved to Brooklyn, New York City, with his family as a child and attended Thomas Jefferson High School, from which he left in his junior year. He later attended Oswego State Teachers College (now SUNY Oswego). He also claimed to have earned a Ph.D. in child psychology from Columbia University in 1941. The university, though, has no record of this.
In other interviews, he claimed to have joined the Merchant Marine prior to World War II and spent time in Italy.
His acting career begins the well documented portion of his life. He worked in burlesque and vaudeville theaters, then on Broadway in the dramas The Night Circus (1958) and One More River(1960), and as the character Moe Shtarker in the musical comedy Do Re Mi (1962). His earliest television work includes appearances on the Beverly Garland crime drama, Decoy, and The Phil Silvers Show, From 1959 to 1963, he appeared in four episodes of ABC's Naked City. His first well-known television role was as Officer Leo Schnauser on the NBC sitcom, Car 54, Where Are You? from 1961 to 1963 (also in the 1994 movie).
Lewis is best remembered as Grandpa on The Munsters, which ran on CBS from 1964 to 1966 and for years later in re-runs. He had a guest role as a clumsy space magician in a Lost in Spaceepisode called "Rocket To Earth". His first role in a movie was playing Machine Gun Manny in Pretty Boy Floyd (1960). He played the role of a bank robber in Green Acres (1971). He also played the character Turkey in They Shoot Horses, Don't They? (1969). Lewis had also played the role of a stern judge in Used Cars (1980) His last role in a movie was Father Hanlon in Night Terror(2002).
Al Lewis caricature by Jim McDermott
Unlike some actors, such as Rob "Meathead" Reiner, Leonard "Spock" Nimoy and Ron "Horshack" Pallilo, Lewis did not mind being typecast. He enjoyed acting out his "Grandpa" character – in the original costume – and got a surprising amount of mileage from such a short-lived role. "Why not?" he said. "It pays the bills."
In 1991, he appeared in a low-budget New Zealand family movie called Grampire (My Grandpa Is a Vampire in the US version) wearing much the same costume as he did in The Munsters. The costume designer was Ngila Dickson, who went on to win an Oscar for her costume designs for Lord of the Rings. From 1987 to 1989, Lewis hosted Super Scary Saturday on TBS in his Grandpa Munster outfit. This would later be parodied in the film Gremlins 2: The New Batch, with the character of "Grandpa Fred" (Robert Prosky). Al Lewis was featured in the Atari 7800 game Midnight Mutants, an action-adventure title with a Halloween theme. His appearance in the game mirrored his Grandpa persona in the Munsters television series.
Lewis married Marge Domowitz in 1956, with whom he had three sons, Dave, Ted and Paul. The marriage ended in divorce in 1977, and in 1984 he married actress Karen Ingenthron, his wife for the remainder of his life on Roosevelt Island.
In 2003, he was hospitalized for an angioplasty, and complications from the surgery led to an emergency bypass and the amputation of his right leg below the knee and all the toes on his left foot. He died on February 3, 2006, of natural causes in a hospital. He was cremated, and his funeral was held at Riverside Church in New York City. His favorite gospel music was played, and his remains were buried on February 18, 2006 in his favorite cigar box.