Charles Samuel Addams was born in Westfield, New Jersey, the son of Grace M. and Charles Huey Addams, a piano-company executive who had studied to be an architect. He was known as “something of a rascal around the neighborhood” as childhood friends recalled. Charles Addams was distantly related to U.S. presidents John Adams and John Quincy Adams, despite the different spellings of their last names, and was a first cousin twice removed to noted social reformer Jane Addams. A house on Elm Street, and another on Dudley Avenue that police once caught him breaking into, are said to be the inspiration for the Addams Family mansion in his cartoons. College Hall, the oldest building on the current campus of the University of Pennsylvania, where Addams studied, was also an inspiration for the mansion. He was fond of visiting the Presbyterian Cemetery on Mountain Avenue. One friend said of him: “His sense of humor was a little different from everybody else’s.” He was also artistically inclined, “drawing with a happy vengeance”, according to a biographer. His father encouraged him to draw, and Addams did cartoons for the Westfield High School student literary magazine, Weathervane. Charles Addams attended Colgate University in 1929 and 1930, and the University of Pennsylvania, where a fine-arts building on campus is named for him, in 1930 and 1931. In front of the building is a sculpture of the silhouettes of Addams Family characters. He then studied at the Grand Central School of Art in New York City in 1931 and 1932.

In 1933, Charles Addams joined the layout department of True Detective magazine, where he had to retouch photos of corpses that appeared in the magazine’s stories to remove the blood from them. Addams complained: “A lot of those corpses were more interesting the way they were.” Addams’ first drawing, a sketch of a window washer, ran in The New Yorker on February 6, 1932, and his cartoons ran regularly in the magazine from 1938, when he drew the first in the series that came to be called The Addams Family, until his death. He was a freelancer throughout that time. During World War II, Charles Addams served at the Signal Corps Photographic Center in New York, where he made animated training films for the U.S. Army. In late 1942, he met his first wife, Barbara Jean Day, who purportedly resembled his cartoon character Morticia Addams. The marriage ended eight years later, after Addams, who hated small children, refused to adopt one. She later married New Yorker colleague John Hersey, author of the book Hiroshima. Charles Addams married his second wife, Barbara Barb (Estelle B. Barb), in 1954. A practicing lawyer, she “combined Morticia-like looks with diabolical legal scheming”, by which she wound up controlling “The Addams Family” television and film franchises and persuaded her husband to give away other legal rights. At one point, she got her husband to take out a US $100,000 insurance policy. Addams consulted a lawyer on the sly, who later humorously wrote: “I told him the last time I had word of such a move was in a picture called Double Indemnity starring Barbara Stanwyck, which I called to his attention.” In the movie, Stanwyck’s character plotted her husband’s murder. The couple divorced in 1956.

The Addams Family television series began after David Levy, a television producer, approached Addams with an offer to create it with a little help from the humorist. All Addams had to do was give his characters names and more characteristics for the actors to use in portrayals. The series ran on ABC for two seasons, from 1964 to 1966. Charles Addams was “sociable and debonair”. A biographer described him as being “a well-dressed, courtly man with silvery back-combed hair and a gentle manner, he bore no resemblance to a fiend”. Figuratively a ladykiller, Addams accompanied women such as Greta Garbo, Joan Fontaine and Jacqueline Kennedy on social occasions. Later, Addams married his third and last wife, Marilyn Matthews Miller, best known as “Tee” (1926–2002), in a pet cemetery. In 1985, the Addamses moved to Sagaponack, New York, where they named their estate “The Swamp”. Charles Addams died on September 29, 1988, at the age of 76, at St. Clare’s Hospital and Health Center in New York City, having suffered a heart attack while still in his car after parking it. An ambulance took him from his apartment to the hospital, where he died in the emergency room. As he had requested, a wake was held rather than a funeral; he had wished to be remembered as a “good cartoonist”. He was cremated, and his ashes were buried in the pet cemetery of his estate “The Swamp”.