Redstone was born to a Jewish family in Boston, Massachusetts, to Belle (née Ostrovsky) and Michael Rothstein. In 1940, at Sumner's behest, his Father agreed to change the family surname from "Rothstein" to "Redstone" ("Red stone" is a literal translation of the German-Jewish name, "Rothstein"). Michael Rothstein owned Northeast Theater Corporation in Dedham, Massachusetts (the forerunner of National Amusements) and the Boston branch of the Latin Quarter Nightclub.
Redstone attended the Boston Latin School, from which he graduated first in his class. In 1944, he graduated from Harvard College, where he completed the studies for his baccalaureate in three years. Later, Redstone served as First Lieutenant in the United States Army during World War II with a team that decoded Japanese messages. After his military Service, he worked in Washington, D.C., and attended Georgetown University Law Center. He transferred to Harvard Law School and received his law degree in 1947.
After completing law school, Redstone served as special assistant to U.S. Attorney General Tom C. Clark (who later served as Associate Justice of the Supreme Court of the United States from 1949 to 1967) and then worked for the United States Department of Justice Tax Division in Washington, D.C. and San Francisco, and thereafter entered private practice. In 1954, he joined his father's theater chain, National Amusements and in 1967, he became CEO of the company. As the company grew, Redstone came to believe that content would become more important than distribution mechanisms: channels of distribution (in varied forms) would always exist, but content would always be essential (Redstone coined the phrase, "Content is king!"). He invested in Columbia Pictures, Twentieth Century Fox, Orion Pictures, and Paramount Pictures (Redstone's Viacom would buy Paramount in the 1990s), all of which turned over huge profits when he chose to sell their stock in the early 1980s.
Looking for a new Business venture, he set his sights on Viacom International, a company which he had already been buying stock in as an investment and was a spin-off of CBS in 1971 after the FCC ruled that television networks could not syndicate programs following their network run. Viacom syndicated most of CBS's in-house productions (such as Hawaii Five-O and Gunsmoke, as well as the pre-1960 Desilu Productions library which CBS acquired in 1960, I Love Lucy being among the acquired programs), but also made a lot of money from syndicating other programs, including most of Carsey-Werner Productions' shows (The Cosby Show, Roseanne, and A Different World), as well as syndicating shows for other companies (Columbia Pictures Television's All in the Family was one notable Example, as was MTM Enterprises' The Mary Tyler Moore Show), and cable channels (Nickelodeon's Double Dare and Finders Keepers (co-syndicated with 20th Television) were two examples).
In 1979, he suffered severe burns in a fire at the Copley Plaza hotel, in Boston, but survived after thirty hours of extensive surgery at Massachusetts General Hospital. Though he was warned that he might never be able to live a normal life again, eight years later he was fit enough to insist on playing tennis nearly every day and to launch a hostile takeover of Viacom. Redstone has discussed the story of surviving the fire as a reflection of his strong determination and will to live.
Viacom also owned MTV Networks (formerly known as Warner-AMEX Satellite Entertainment), which owned MTV and Nickelodeon. In addition, other properties included Showtime Networks (a pay-television network similar to HBO and Cinemax) and The Movie Channel. Viacom acquired MTV Networks in 1985 for $550 million from Steve Ross' Warner Communications. (WCI bought American Express' share and then sold the entire entity to Viacom, as they felt that they could not make a lot of money from the venture and the bias of a studio owning cable channels would be a conflict of interest. The studio's stance changed in 1995, when as Time Warner it bought Turner Broadcasting.)
Redstone's next acquisition was the purchase of Paramount Communications (previously Gulf+Western), parent of Paramount Pictures in 1993. He engaged in a bidding war with Barry Diller (former board member of Vivendi Universal and CEO of IAC/InterActiveCorp) and John Malone (president of TCI/Liberty Media), and had to raise his bid three times. Some say that Redstone overpaid, but after he shed certain assets — the Madison Square Garden properties (which included the NBA's NY Knicks and the NHL's NY Rangers) to Charles Dolan's Cablevision and Simon & Schuster's educational publishing units to Pearson PLC — for almost $4 billion, Redstone turned Viacom's expenditure into a substantial profit. Under Redstone's leadership, Paramount went on an almost ten-year streak of record performance, producing such films as Saving Private Ryan, Titanic (one of the highest-grossing films of all time and Best Picture Academy Award winner), Braveheart (Best Picture Academy Award), and Forrest Gump (also a Best Picture winner) and the creation of the hugely successful Mission: Impossible series of pictures.
One of Redstone's largest acquisitions came in the form of Viacom's former parent, CBS. Former Viacom President and COO Mel Karmazin (who was then the President of CBS) proposed a merger to Redstone on favorable terms and after the merger completed in 2000, Viacom had some of the most Diversified businesses imaginable. Viacom had assets in the form of broadcast networks (CBS and UPN), cable television networks (MTV, VH1, Nickelodeon, MTV2, Comedy Central, BET, Nick at Nite, Noggin/The N, TV Land, CMT, and Spike TV), pay television (Showtime and The Movie Channel), radio (Infinity Broadcasting, which produced the immensely popular Howard Stern radio shows), outdoor advertising, motion pictures (Paramount Pictures), and television production (Spelling Entertainment, Paramount Television, Big Ticket Entertainment, CBS Productions, and Viacom Productions), and King World Productions (a syndication unit, which notably syndicates the runaway daytime hit, The Oprah Winfrey Show, as well as Dr. Phil, Wheel of Fortune, and Jeopardy!), among others.
Redstone's autobiography, A Passion to Win (co-written with author Peter Knobler), was published in 2001 by Viacom's Simon & Schuster. This book details everything from Redstone's life as a young boy in Boston to the difficult takeover of Viacom and the problems he overcame in purchasing and managing both Blockbuster Video and Paramount Pictures. The book also recounts the legendary CBS merger (Viacom was a spin-off company of CBS to syndicate its programs, and the subsidiary bought the parent almost 30 years later).
A longtime Democratic supporter, with a history of donating to many Democratic campaigns, including regular donations to Ted Kennedy, John Kerry, and former Senate Majority Leader Tom Daschle, Redstone endorsed Republican George W. Bush over Kerry in the 2004 Presidential election, allegedly because he argued that Bush would be better for his company and the economy. Despite this public endorsement, he donated money to Kerry during the primaries and was involved in the Rathergate scandal meant to hurt Bush's reelection.
Redstone made arrangements to step down as CEO of Viacom in 2006. After Mel Karmazin resigned in 2004, two heirs apparent were named: Co-President and Co-COO Leslie Moonves (who was number 2 to Karmazin at CBS; he was the former head of Warner Bros. Television and before that, Lorimar Television) and Co-President and Co-COO Tom Freston (who had been President and CEO of MTV Networks since 1987 and had been with the company since the formation of MTV Networks' precursor company, Warner-AMEX Satellite Entertainment). After the Viacom split was approved by the board on June 14, 2005, Moonves headed CBS, and Freston headed the new Viacom, Inc.
On September 5, 2006, Redstone removed Freston as President and CEO of Viacom and replaced him with Director and former Viacom counsel Philippe Dauman. Redstone also brought back former CFO Tom Dooley. This was surprising to many, as Freston had been seen by many as Redstone's heir apparent, and Redstone had touted that Freston would run the company after he retired. Redstone publicly stated that he let Freston go because of Viacom's lack of aggressiveness in the digital/online arena, lack of contact with Investors, and a lackluster upfront (coupled with falling viewership) at MTV Networks.
In 1947, he married Phyllis Gloria Raphael. In 1999, they divorced. They had two children: Brent Redstone and Shari Redstone. Three years after his divorce, he married Paula Fortunato, a former primary school Teacher 39 years his junior. Sumner Redstone filed for divorce from her on October 17, 2008. Their divorce was finalized on January 22, 2009. Redstone owns a house in the Beverly Park area of Beverly Hills, California, which he purchased in 2002 for $14,500,000.
In July 2010, Redstone was caught on tape trying to find the source of an apparently embarrassing leak within his own MTV. Redstone offered money and protection to a Journalist if he would give up his source. Redstone had been pushing the MTV management to give more airtime to the band the Electric Barbarellas. On the message, Redstone tells the reporter that "we're not going to kill" the source, adding "We just want to talk to him". The 87-year-old Redstone also tells the reporter he will be "well rewarded and well protected" if he would reveal the source. Peter Lauria told NBC's Today show he would not do it. Viacom Inc. spokesman, Carl Folta confirmed to Today that it was Redstone's voice on the message and said the mogul had made a mistake. A Viacom source told the New York Post, "Sumner wants to be consequential. Sumner is really proud of what he did. This guy is loving it… He likes people to know he's still alive".
On June 1, 2012, Paramount Pictures renamed the Administration Building on the studio lot the Sumner Redstone Building in a dedication ceremony attended by employees of Paramount Pictures and Viacom.
In August 2015, Redstone split with his live-in girlfriend, Sydney Holland, after five years together.
In February 2016, at age 92, after a court-ordered examination by a geriatric Psychiatrist whose findings were not publicly disclosed, Redstone relinquished the chairmanship of CBS to Moonves and the chairmanship of Viacom to Dauman. In May 2016, Los Angeles Superior Court Judge David Cowan dismissed a lawsuit alleging that Redstone was mentally incompetent, although the judge stated it was "not in dispute that Redstone suffers from either mild or moderate dementia"; in addition to this, his speech is now severely impaired. Two weeks later, another such lawsuit was filed in Massachusetts.