The hall-of-fame golfer, who turned 54 on April 9 (on the third round of the 2011 Masters) is the youngest Masters champion to die.
Horton Smith, the winner of the inaugural Masters in 1934, had been the youngest. He was 55 when he died in 1963.
Ballesteros, who died in his native Pedrena, Spain from of respiratory complications from the brain tumor diagnosed in late 2008,
He won the Masters in 1980 and 1983 and was annually a threat until the early 1990s.
"With the passing of Seve Ballesteros, the Masters Tournament loses one of its great champions," Augusta National Golf Club and Masters Tournament chairman Billy Payne said in a statement.
"Best known for his fearless and heroic play, Seve annually showcased his brilliance at Augusta National, much to the enjoyment of the millions of fans he inspired around the world," Payne said. "He leaves an indelible mark on the history of our Tournament and will be dearly missed."
Ballesteros loved the Masters, saying he dreamed of winning the tournament when he would hit rocks with the only club he had, a 3-iron, on the beach as a youngster.
During his early years at Augusta National, Ballesteros would visit the pro shop and buy a visor with the Masters logo and wear it during the tournament.
PGA Tour commissioner Tim Finchem said Ballesteros' impact on golf "will be felt long into the future, and we join his family and many friends in mourning his passing."
Ballesteros' tumor was discovered in October 2008 after he passed out in an airport. Four surgeries were needed on the tumor and he underwent chemotherapy. At the time, Ballesteros called it "the hardest challenge of my life."
After he survived the surgeries - one of which lasted nearly seven hours - Ballesteros said he had been given "a mulligan" in life and made a few public appearances the following year.
Ballesteros won five major championships, a record 50 European Tour events, four PGA Tour events and helped turned golf into a global game through his major championship victories and his sterling play in the Ryder Cup.
"This is such a very sad day for all who love golf," European Tour chief executive George O'Grady said on the tour's Web site. "We have all been so blessed to live in his era.
"Seve's unique legacy must be the inspiration he has given to so many to watch, support, and play golf, and finally to fight a cruel illness with equal flair, passion and fierce determination," O'Grady said.
On his twitter account, World No. 1 Lee Westwood, of England, wrote: "It's a sad day. Lost an inspiration, genius, role model, hero and friend. Seve made European golf what it is today. RIP Seve."
Even casual fans took notice of Ballesteros in his prime because of his vibrant personality and passion for the game.
"He had such charisma about him; I don't think you can manufacture that," said 1987 Masters Tournament champion Larry Mize, who beat Ballesteros and Greg Norman in a sudden-death playoff for his green jacket.
"You either have it or you don't," Mize said of charisma. "He was what they like to call swashbuckling. Just the way he walked down the fairway. He was an exciting player to watch. You were drawn to him."
That was never more true than in the final round of the 1983 Masters. In a Monday finish, Ballesteros started the round one shot behind Raymond Floyd and Craig Stadler.
Ballesteros was 4-under through four holes (birdie, eagles, par, birdie) . He shot 69 and won by four shots.
"I call him the Cirque du Soleil of golf," three-time Masters champion Nick Faldo, of England, said on CBS' broadcast of the Wells Fargo Championship. on Saturday. "For me, he was the greatest show. He had everything. We will never have another Seve.
"Arnold Palmer was Arnold, yes, he was special," Faldo said. "He had charisma. Seve had charisma, flair, good looks, the walk, the face, the eyes. You had so much."
There were recent signs that Ballesteros health was declining. He had hoped to play an exhibition of former British Open champions at the 2010 British Open at St. Andrews, but doctors ruled it out.
At the Champions Dinner on the Tuesday night of the 2011 Masters, defending champion Phil Mickelson's menu included a Spanish dish in Ballesteros' honor.
And after the champions had eaten, two-time Masters champion Jose Maria Olazabal gave a sad update on his fellow Spaniard and friend.
"Jose filled us in," Mize said. "He said it wasn't really out yet, but basically it wasn't good and they didn't think he (Ballesteros) would make it through the year. He had some kind words from Seve about some of the bigger names."
"Ollie made a wonderful speech and he went around the table conveying Seve's wishes to everybody, his memory of everybody and how he remembered you as a character and that sort of thing," Faldo said on CBS. "We kind of sensed it,"
"He hated to tell us," Mize said of Olazabal. "He was able to get through it, but he was giving it with a heavy heart."
And on Friday, Ballesteros' family issued a statement saying there had been a "severe deterioration" in his health.
Olazabal and fellow Spaniard Miguel Angel Jimenez were crying as they finished their rounds Friday in the Spanish Open after hearing the news of Ballesteros' condition.
Ballesteros' passing was mourned all other the world, and at pro golf tournaments. At the Spanish Open, the pin flags were lowered to half-staff and a moment of silence was held. On one scoreboard was the note "Seve forever."
In Saturday's third round of the Spanish Open, Olazabal shot 75 and called it " the most difficult round of my life. It was very tough to make it to the first tee and hit the first drive."
Playing partner Colin Montgomerie said Olazabal was "in floods of tears most of the day. He has lost an older brother almost."
Most of the players in the Spanish Open, as well as those at the PGA Tour's Wells Fargo Championship, the Champion's Tour's Regions Tradition and the Nationwide Tour's Stadion Classic in Athens, Ga., wore black ribbons in his honor.
Ballesteros wowed the golf world with a style that was right out of Arnold Palmer's go-for-broke book. Ballesteros was a wayward driver who hit miraculous recovery shots, which was perfectly suited for British Open venues and Augusta National Golf Club, which had wide-open fairways during his prime.
"He had everything he needed (at Augusta National)," said Mize.
"He was a little wild, but he could get away with it," Mize said. "Augusta requires great iron play and he was a great iron player. The creativity and imagination is key at Augusta, especially when you get around the green. His short game is legendary. It was right up his alley - that's why he's a multiple winner."
In the 1987 Masters, Ballesteros bowed out of the sudden-death playoff with Mize and Norman with a three-putt bogey on the first hole, No. 10 on the course. Mize then won it on the next hole with his famous 140-foot chip-in birdie.
"The biggest thing I remember is he came over and shook my hand and wished me good luck," Mize said. "That was very nice of him. I appreciated that. We always got along well."
The 1987 Masters wasn't the only time Mize got the better of Ballesteros.
In Mize's lone Ryder Cup appearance, in 1987 at Muirfield Village Golf Club in Columbus, Ohio, Mize and Hal
Sutton beat Ballesteros and Olazabal 2 and 1 in a team match. It was Ballesteros' only loss in five matches as he led Europe to its first Ryder Cup victory on U.S. soil.
Ballesteros and Olazabal's career record as a Ryder Cup team was 11-2-2.
"We were the first to beat them; it was fun," Mize said. "That was a blast. You don't forget about beating those two guys. They were a powerhouse."
When he won the 1980 Masters, Ballesteros was the youngest winner (age 23) and the second international player to win the Masters and the first European. His victory opened the floodgates at Augusta National - Europeans won nine of the next 16 green jackets.
Ballesteros played in 18 Masters. He was a contender through 1990, when he tied for seventh place.
Back problems led to poor play and he never made a cut after the 1996 event. He was unable to play from 2004-2006, but came back for a final appearance in 2007, shooting 86-80-166.
Later that summer, at the British Open, he announced his retired from golf at age 51.