Jack Kent Cooke, who started his career peddling encyclopedias in Canada and went on to build empires in newspapers, cable television and sports and to own the Los Angeles Lakers, the Washington Redskins and the Chrysler Building, died yesterday at George Washington University Hospital in Washington. He was 84.

Mr. Cooke collapsed at his estate in northwest Washington. Soon after arriving at the hospital he died of congestive heart failure resulting from heart disease, a hospital spokeswoman said.

In a tumultuous lifetime in the fast lanes of Los Angeles and Washington, where he reigned as a superstar host in his deluxe football box, Mr. Cooke set records for buying and selling properties and athletes while maintaining a life style of perpetual motion.

He was worth an estimated $825 million, and collected art, vintage automobiles, race horses and sherry. He signed such legendary athletes as Wilt Chamberlain, Kareem Abdul-Jabbar, Jerry West, Elgin Baylor and Joe Theismann to what were considered astronomical contracts, and he signed George Allen to run the Redskins for $125,000 a year, at the time a record amount for a football coach. He owned palatial homes in Bel Air, Calif., and in the Virginia countryside, the Elmendorf Farm in Kentucky and a 13,000-acre ranch in Southern California. He was married four times, including one marriage that ended with a settlement of $41 million, a figure that landed him in ''The Guinness Book of Records.''

He was not one of the idle rich and, as he entered his 80's, he became increasingly occupied with yet another large-scale project: a $160 million, 78,600-seat stadium for his Redskins in the countryside of Prince George's County between Washington and Baltimore. After battling local government for a decade, he finally reached a deal to build the stadium in 1995. It is scheduled to open this season.

He once looked back on the frenzy in his life, and concluded: ''I retired once, which taught me never to do that again.'' When a writer sought to include him in a book about the world's five greatest salesmen, he declined with the comment: ''Sir, I am not one of five anything.''

The man behind all the deals was short, dapper, white-haired, craggy and either charming or bullying, depending on the needs of the moment. He tended to be unyielding and sometimes autocratic in wheeling and dealing through business blockbusters. He had an obsession with language, and often corrected people. He tended to verbally punctuate other people's sentences, or even his own, as he did when replying to a question about the Redskins: ''The club is in first-class hands. Colon. Edward Bennett Williams. Period.''

He was proud of his Canadian origins, his sports stakes in California and his high visibility in Washington. His luxury box at Robert F. Kennedy Stadium was regularly filled with senators, governors and other Washington figures such as Colin Powell, George McGovern, Eugene McCarthy, George Will and John Warner.

Even if his deals had not changed skylines and landscapes, he would have gone down in sports history for a move that opened an entertainment era: he financed the first fight between Muhammad Ali and Joe Frazier in 1971 by setting up an extensive closed-circuit television network. The deal heralded the $100 million gates of today's pay-per-view events.

The idea was put to him by Jerry Perenchio, a Hollywood agent who represented Elizabeth Taylor, Richard Burton and other movie stars. ''This fight is entertainment,'' Perenchio said. ''It's like 'Gone With the Wind.' You could show it on the side of a supermarket, and people would come to see it.''

Mr. Cooke put up $4.5 million to guarantee the fighters' purses of $2.5 million each, and the rest was pledged by Madison Square Garden. When officials outlined the revolutionary parameters of the fight, with a million and a half seats at $10 and up, plus foreign rights around the world, they said they expected a gross of between $20 million and $30 million. (It did gross more than $30 million.)

Ali, never one to miss a nuance, promptly shrieked: ''Thirty million dollars. Frazier, we've been taken. They got us cheap.''

Jack Kent Cooke was born in Hamilton, Ontario, on Oct. 25, 1912. His father lost his picture-frame business in the Depression in 1934, so Mr. Cooke gave up youthful pursuits such as football, hockey and playing the saxophone in a band and went to work selling encyclopedias door to door. Three years later, he was working for a radio station in Stratford, Ontario, where he caught the attention of Roy Thomson, who was building an empire in communications. Mr. Cooke went to work for him and soon had major resources.

He began making his fortune by investing in dying radio stations and reviving them. He acquired newspapers and revitalized defunct magazines. He took over a plastics company and made it work. He was a millionaire at 31, and headed for what he called his ''second life'' in California. It quickly became a life of landmark deals that established him in major league sports.

In 1951, he bought the Toronto Maple Leafs baseball team of the International League. In 1960, he acquired a 25 percent interest in the Washington Redskins football team for $300,000. The same year, avoiding the customary five-year residency wait, he became a United States citizen by a special act of Congress. In 1965, he paid $5.1 million for the Los Angeles Lakers basketball team. In 1966, he paid $2 million for the Kings hockey team and helped import hockey from Canada to Southern California. In 1967, he built and opened his own arena, the $16 million Inglewood Forum.

His empire-building was interrupted by a heart attack in 1973, a divorce by his wife of 41 years in 1979 and the $41 million settlement.

He moved to Las Vegas, Nev., and in 1979 executed a stunning series of deals: he sold the Lakers, the Kings and his ranch in the Sierra foothills for $67 million to the real-estate titan Jerry Buss, bought the Chrysler Building in Manhattan for $87 million and assumed operating control of the Redskins in 1980 from Mr. Williams. In 1985, he added The Los Angeles Daily News to his holdings.

In Washington, he lived his ''third life'' as host to waves of the capital's power brokers at Robert F. Kennedy Stadium. The Redskins, as dynamic on the field as he was off it, won the Super Bowl in 1983, 1988 and 1992.

The business blockbusters continued at the same breathtaking pace. In 1981, he merged his Teleprompter Corporation with the Westinghouse Electric Corporation for $656 million. Later in the same decade, he sold his cable-television interests in 19 states for $1.6 billion. And in 1987, he paid $47 million to buy the Elmendorf Farm in Lexington, one of Kentucky's leaders in breeding and racing thoroughbreds.

Mr. Cooke's four marriages often took twists worthy of the tabloids. His first marriage to his childhood sweetheart, Barbara Jean Carnegie, ended when she sued for divorce and won a $41 million settlement. They had two sons, Ralph and John, but after the divorce, Ralph became estranged from his father for 10 years. He died in 1995. Ralph's son, Jack Kent Cooke 2d, who had aspired to become president of the Kings, died in 1989 of liver disease at 26.

In 1980, Mr. Cooke married Jeanne Maxwell Williams, a sculptor from Las Vegas, but the marriage ended in divorce within the year. In 1987, he married Suzanne Martin of Middleburg, Va., who was 44 years his junior. The marriage lasted 73 days. They had one daughter, Jacqueline.

And in 1990, he married Marlene Ramallo Chalmers of Bolivia, who was 40 years his junior and a friend of his third wife, and who had served three and a half months in Federal prison for conspiracy to import cocaine.

Mr. Cooke is survived by Marlene, his son John and his daughter Jacqueline.

Mr. Cooke generally accepted the bad times with the good in a life of blurring activity. Once, citing his favorite author, he summed up his reaction to it all and said, ''My life is better than any F. Scott Fitzgerald novel you have ever read.''

Jack kent Cooke