Bruce Ratner (born January 23, 1945, in Cleveland, Ohio) is an American real estate developer, philanthropist, and former minority owner of the NBA's Brooklyn Nets.

Ratner was born into a Jewish family in the Cleveland metropolitan area, the son of Anne (née Spott) and Harry Ratner, one of eight children to immigrate to the US from Poland. Four of his paternal uncles, Leonard Ratner, Charles Ratner, Max Ratner, and Nate Shafran along with his aunt, Fannye Ratner Shafran founded Forest City Enterprises in 1920; originally a construction materials company it eventually evolved into construction and then into real estate development. Ratner's older brother was the late civil liberties attorney and activist Michael Ratner and his sister is Ellen Ratner, a former news analyst for Fox News. Ratner graduated from Harvard College in 1967, and earned a Juris Doctor from Columbia University in 1970.

After graduating law school in 1970, Ratner was the director of the Model Cites program until 1973. Simultaneously, Ratner served as the head of the Consumer Protection Division in the administration of New York City mayor John Lindsay. From 1974 to 1978, Ratner taught at NYU's law school. Following his teaching career, Ratner returned to work for the City of New York. Under Mayor Ed Koch he became consumer affairs commissioner where he went after corrupt merchants, repairmen and alarm companies. Ratner served as Consumer of Public Affairs for 4 years beginning in 1978. He then turned to developing real estate.

In 1985, he co-founded Forest City Ratner, with the family's parent company (Forest City Enterprises which funded 70 percent of the capital. He developed the $1 billion complex of nine buildings in downtown Brooklyn called MetroTech. He supervised the building of a 393,000 square-foot shopping mall at the intersection of Atlantic and Flatbush Avenues in the 1990s. Bruce Ratner used eminent domain to seize private property (homes, businesses) for the arena and development, sparking major protests. He bought the New Jersey Net to build Barclay’s arena. He had Jay-Z owns an estimated 0.15 percent of the Nets. The real owner is Mikhail D. Prokhorov, the Russian oligarch who obligingly took 80 percent of the team and 45 percent of the arena off Mr. Ratner’s hands for a cool $223 million. This investment along with other dealings had an impact on Forest City Enterprises the parent company.

Ratner's firm, Forest City Ratner, began construction of Metrotech Center in June 1989. Brooklyn journalist Dennis Holt labeled June 26, 1989, as the start of a "new Brooklyn." The complex totals over 5.8 million square feet of office space. The creation of this office space brought at least 22,000 jobs to the borough.

In 2007, Ratner's company, Forest City Realty Trust completed construction and opened the New York Times Building. The skyscraper, located at 620 Eighth Avenue, is the eleventh-tallest building in the city, tied with the Chrysler Building.

In 2011, Ratner's company, Forest City Realty Trust completed construction and opened New York By Gehry. Designed by Frank Gehry, the building stands 76 stories and 870 ft tall. In his review of the building, New York Times architecture critic Nicolai Ouroussoff proclaimed it "the finest skyscraper to rise in New York since Eero Saarinen's CBS Building went up 46 years ago."

Ratner first became owner of the Nets when he headed an ownership group that purchased the franchise from YankeeNets for $300 million. Ratner's group beat out an ownership group led by Charles Kushner and former New Jersey governor Jon Corzine. Ratner relocated the Nets to New York City, specifically to build an arena in the Prospect Heights neighborhood of Brooklyn even though there was desire to keep them in New Jersey and strong neighborhood protests to keep them out of Brooklyn.