In the 1960s, the magazine's readership began to decline. In 1969, The Saturday Evening Post folded for two years before being revived as a quarterly publication with an emphasis on medical articles in 1971.

As of the late 2000s, The Saturday Evening Post is published six times a year by the Saturday Evening Post Society, which purchased the magazine in 1982. The magazine was redesigned in 2013.

The Saturday Evening Post was first published in 1821 in the same printing shop at 53 Market Street in Philadelphia, where the Benjamin Franklin-founded Pennsylvania Gazette was published in the 18th century. While the Gazette ceased publication in 1800, ten years after Franklin's death, the Post links its history to the original magazine.

Cyrus H. K. Curtis, publisher of the Ladies' Home Journal, bought the Post for $1,000 in 1897. Under the ownership of the Curtis Publishing Company, the Post grew to become the most widely circulated weekly magazine in the United States. The magazine gained prominent status under the leadership of its longtime editor George Horace Lorimer (1899–1937).

The Saturday Evening Post published current event articles, editorials, human interest pieces, humor, illustrations, a letter column, poetry with contributions submitted by readers, single-panel gag cartoons, including Hazel by Ted Key, and stories by leading writers of the time. It was known for commissioning lavish illustrations and original works of fiction. Illustrations were featured on the cover and embedded in stories and advertising. Some Post illustrations continue to be reproduced as posters or prints, especially those by Norman Rockwell.

In 1954, it published its first articles on the role of the U.S. in deposing Mohammad Mosaddegh, Prime Minister of Iran, in 1953. The article was based on materials leaked by CIA director Allen Dulles.

The Post readership began to decline in the late 1950s and 1960s. In general, the decline of general interest magazines was blamed on television, which competed for advertisers and readers' attention. The Post had problems retaining readers: the public's taste in fiction was changing, and the Post's conservative politics and values appealed to a declining number of people. Content by popular writers became harder to obtain. Prominent authors drifted away to newer magazines offering more money and status. As a result, the Post published more articles on current events and cut costs by replacing illustrations with photographs for covers and advertisements.

In 1967, The magazine's publisher, Curtis Publishing Company, lost a landmark defamation suit, Curtis Publishing Co. v. Butts 388 U.S. 130 (1967), resulting from an article, and was ordered to pay $3,060,000 in damages to the plaintiff. The Post article implied that football coaches Paul "Bear" Bryant and Wally Butts conspired to fix a game between the University of Alabama and the University of Georgia. Both coaches sued Curtis Publishing Co. for defamation, each initially asking for $10 million. Bryant eventually settled for $300,000 while Butts' case went to the Supreme Court, which held that libel damages may be recoverable (in this instance against a news organization) when the injured party is a non-public official, if the plaintiff can prove that the defendant was guilty of a reckless lack of professional standards when examining allegations for reasonable credibility. (Butts was eventually awarded $460,000.)^]

William Emerson was promoted to editor-in-chief in 1965 and remained in the position until the magazine's demise in 1969.

In 1968, Martin Ackerman, a specialist in troubled firms, became president of Curtis after lending it $5M. With the magazine still in dire financial straits, Ackerman announced that Curtis would reduce printing costs by cancelling the subscriptions of roughly half of its readers. Those who lost their subscriptions were offered a free transfer to a subscription to Life magazine; Life publisher Time, Inc. paid Curtis $5M for the exchange, easing the company's mounting debts. The move was also widely seen as an opportunity for Curtis to abandon older and more rural readers, who were less valuable to the Post's advertisers. Columnist Art Buchwald lampooned the decision, suggesting that "if the Saturday Evening Post considered you a deadbeat, you didn't have much choice but to either pretend you were still getting the magazine and live a lie, or move out of the neighborhood before anyone found out."

These last-ditch efforts failed to save the magazine, and Curtis announced in January 1969 that the February 8 issue would be the magazine's last. Ackerman stated that the magazine had lost $5M in 1968 and would lose a projected $3M in 1969. In a meeting with employees after the magazine's closure had been announced, Emerson thanked the staff for their professional work and promised "to stay here and see that everyone finds a job".

At a March 1969 post-mortem on the magazine's closing, Emerson stated that The Post "was a damn good vehicle for advertising" with competitive renewal rates and readership reports and expressed what The New York Times called "understandable bitterness" in wishing "that all the one-eyed critics will lose their other eye". Otto Friedrich, the magazine's last managing editor, blamed the death of The Post on Curtis. In his Decline and Fall (Harper & Row, 1970), an account of the magazine's final years (1962–69), he argued that corporate management was unimaginative and incompetent. Friedrich acknowledges that The Post faced challenges while the tastes of American readers changed over the course of the 1960s, but he insisted that the magazine maintained a standard of good quality and was appreciated by readers

In 1970, control of the debilitated Curtis Publishing Company was acquired from the estate of Cyrus Curtis by Indianapolis industrialist Beurt SerVaas. SerVaas relaunched the Post the following year on a quarterly basis as a kind of nostalgia magazine.

In early 1982, ownership of the Post was transferred to the Benjamin Franklin Literary and Medical Society, founded in 1976 by the Post's then-editor, Corena "Cory" SerVaas (wife of Beurt SerVaas). The magazine's core focus was now health and medicine; indeed, the magazine's website originally noted that the "credibility of The Saturday Evening Post has made it a valuable asset for reaching medical consumers and for helping medical researchers obtain family histories. In the magazine, national health surveys are taken to further current research on topics such as cancer, diabetes, high blood pressure, heart disease, ulcerative colitis, spina bifida, and bipolsorder."^[21] Ownership of the magazine was later transferred to the Saturday Evening Post Society; SerVaas headed both organizations. The range of topics covered in the magazine's articles is now wide, suitable for a general readership.

By 1991, Curtis Publishing Company had been renamed Curtis International, a subsidiary of SerVaas Inc., and had become an importer of audiovisual equipment. Today the Post is published six times a year by the Saturday Evening Post Society, which claims 501(c)(3) non-profit organization status.