Stephen Alan Wynn (né Weinberg; born January 27, 1942) is an American real estate developer and art collector. He was known for his involvement in the luxury casino and hotel industry, prior to being forced to step down in 2018. Early in his career he oversaw the construction and operation of several Las Vegas and Atlantic City hotels, including the Golden Nugget, the Golden Nugget Atlantic City, The Mirage, Treasure Island, the Bellagio, and Beau Rivage in Mississippi, and he played a pivotal role in the development of the Las Vegas Strip in the 1990s.

In 2000, Wynn sold his company, Mirage Resorts, to MGM Grand Inc., resulting in the formation of MGM Mirage (now MGM Resorts International). Wynn later took his company Wynn Resorts public in an initial public offering and was Wynn Resorts' CEO and Chairman of the Board until February 6, 2018, when he announced his resignation. He is a prominent donor to the Republican Party and was the finance chair of the Republican National Committee from January 2017 to January 2018, when he resigned amid sexual misconduct allegations, which Wynn has denied. On February 6, 2018, Wynn stepped down as CEO of Wynn Resorts.

Through Wynn Resorts, he has overseen the construction and development of several luxury resorts, opening Wynn Las Vegas in 2005, Wynn Macau in 2006, Encore Las Vegas in 2008, Encore at Wynn Macau in 2010 and Wynn Palace in Macau in 2016, and Wynn Everett near Boston which opened in June 2019 under the name Encore Boston Harbor. In 2006, Wynn was inducted into the American Gaming Association Hall of Fame. As of April 2025, Wynn's net worth was estimated by Forbes at $3.7 billion. Steve Wynn collects fine art, including pieces by artists such as Picasso and Claude Monet.

Steve Wynn was born Stephen Alan Weinberg on January 27, 1942, in New Haven, Connecticut, to a Jewish family. His father, Michael, owned a chain of bingo parlors in the eastern United States. His mother Zelma (née Kutner), was from Maine. Wynn’s father changed the family's last name in 1946 from "Weinberg" to "Wynn" when Steve was 4 years old "to avoid anti-Jewish discrimination". Wynn was raised in Utica, New York, and graduated from The Manlius School, a private boys' school east of Syracuse, New York, in 1959.

After high school, Wynn studied English literature at the University of Pennsylvania, where he was a member of the Sigma Alpha Mu fraternity. Wynn graduated in 1963 with a Bachelor of Arts. Shortly before graduation, his father died during heart surgery, leaving $350,000 in gambling debts. Wynn, who had been accepted into Yale Law School, relinquished his admission and instead took over his family's bingo parlor in Waysons Corner, Maryland.

In 1967, Wynn and his family moved to Las Vegas where he purchased a small stake in the Frontier Hotel and Casino. That year he met E. Parry Thomas, the president of the Bank of Las Vegas, which was the only bank at the time willing to extend loans to Las Vegas casinos, and Thomas helped finance several of Wynn's early land deals.

In 1971, Wynn bought a controlling interest in the Golden Nugget Las Vegas, one of the oldest casinos in the city. His company stake increased so that, in 1973, he became the majority shareholder, and the youngest casino owner in Las Vegas. In 1977 he opened the Golden Nugget's first hotel tower, followed by several others. Frank Sinatra was a periodic headliner at the Golden Nugget, and Wynn has since maintained a relationship with the Sinatra family, even naming a restaurant at Encore "Sinatra".

In 1980, Wynn began construction on the Golden Nugget Atlantic City in Atlantic City, New Jersey. It was Atlantic City's first and only "locals casino" and the city's sixth casino after the city legalized gambling in 1976. Joel Bergman, who designed Wynn's other resorts, designed the Golden Nugget. Though at its opening it was the second smallest casino in the city, by 1983 it was the city's top earning casino. Wynn sold the Atlantic City Golden Nugget in 1987 for $440 million.