Richard Jay Potash (June 26, 1946 – November 24, 2018) was an American stage magician, actor, and writer. In a 1993 profile for The New Yorker, Mark Singer called Jay "perhaps the most gifted sleight of hand artist alive". In addition to sleight of hand, he was known for his card tricks, card throwing, memory feats, and stage patter. He also wrote extensively on magic and its history. His acting credits include The Prestige, The Spanish Prisoner, Mystery Men, Heist, Boogie Nights, Tomorrow Never Dies, Heartbreakers, State and Main, House of Games, Magnolia, Deadwood and Sneaky Pete. In 2015, he was the subject of an episode of PBS's American Masters, the only magician ever profiled in the series.

Jay was born in the New York City borough of Brooklyn to Shirley (Katz) and Samuel Potash. A member of a middle-class Jewish family, he grew up in Elizabeth, New Jersey. He rarely spoke publicly about his parents, but did share an anecdote: "My father oiled his hair with Brylcreem and brushed his teeth with Colgate", Jay recalled. "He kept his toothpaste in the medicine cabinet and the Brylcreem in a closet about a foot away. Once, when I was ten, I switched the tubes. All you need to know about my father is that after he brushed his teeth with Brylcreem he put the toothpaste in his hair."

During an interview on the National Public Radio program Fresh Air with Terry Gross, Jay said that possibly "the only kind memory I ever had of my parents" was when they secretly hired one of his idols, magician Al Flosso, to perform at his bar mitzvah. Jay's grandfather, Max Katz, was a certified public accountant and amateur magician who introduced Jay to magic.

Jay first performed in public at the age of seven, in 1953, when he appeared on the television program Time for Pets. He is most likely the youngest magician to perform a full magic act on TV, the first magician to ever play comedy clubs, and probably the first magician to open for a rock and roll band. At New York's Electric Circus in the 1960s, he performed on a bill between Ike and Tina Turner and Timothy Leary, who lectured about LSD.

During the 1960s and 70s, Jay lived in Ithaca, New York, performing while also intermittently attending the Cornell University School of Hotel Administration, but later moved to the Los Angeles area.

He quickly developed a following among magic aficionados, and a reputation for sleight-of-hand feats that baffled even his colleagues. In his 1993 New Yorker profile of Jay, Mark Singer related the following story from playwright David Mamet and theater director Gregory Mosher:

Some years ago, late one night in the bar of the Ritz-Carlton Hotel in Chicago, [Jay] was performing magic with a deck of cards. Also present was a friend of Mamet and Mosher's named Christ Nogulich, the director of food and beverage at the hotel. After twenty minutes of disbelief-suspending manipulations, Jay spread the deck face up on the bar counter and asked Nogulich to concentrate on a specific card but not to reveal it. Jay then assembled the deck face down, shuffled, cut it into two piles, and asked Nogulich to point to one of the piles and name his card. "Three of clubs," Nogulich said, and he was then instructed to turn over the top card. He turned over the three of clubs. Mosher, in what could be interpreted as a passive-aggressive act, quietly announced, "Ricky, you know, I also concentrated on a card." After an interval of silence, Jay said, "That's interesting, Gregory, but I only do this for one person at a time." Mosher persisted: "Well, Ricky, I really was thinking of a card." Jay paused, frowned, stared at Mosher, and said, "This is a distinct change of procedure." A longer pause. "All right—what was the card?" "Two of spades." Jay nodded, and gestured toward the other pile, and Mosher turned over its top card. The deuce of spades. A small riot ensued.

Three of Jay's one-man shows, Ricky Jay and His 52 Assistants, Ricky Jay: On the Stem, and Ricky Jay: A Rogue's Gallery, were directed by Mamet, who also cast Jay in a number of his films.