The Spaniard, whose fearless brilliance won him five major titles and inspired a generation of players worldwide, died peacefully surrounded by his family at his home in Pedrena, northern Spain. His funeral will be held on Wednesday.
World number one Lee Westwood described Ballesteros as an "inspiration, genius, role model, hero and friend," in one of many warm tributes that poured in from the golfing world and beyond.
"Seve made European golf what it is today," Westwood added on his Twitter feed. "RIP Seve." Tiger Woods said he was deeply saddened to learn of the death of a man who played with unique ability.
"Seve was one of the most talented and exciting golfers to ever play the game," Woods said on Twitter. "His creativity and inventiveness on the golf course may never be surpassed." The death of Ballesteros was keenly felt at the Spanish Open being played in Terrassa in the north east of the country, where players wore black ribbons and observed a minute's silence.
While flags at the course were flying at half-mast, Jose Maria Olazabal and Miguel Angel Jimenez embraced on the practice range at the start of the day as they remembered their friend and fellow Spaniard.
"What impressed me most in Seve was his strength, his fighting spirit and the passion he put into everything he did," Olazabal told reporters.
A winner of three British Opens and two Masters titles, Ballesteros also helped revive Europe's fortunes in the Ryder Cup, breathing new life into the team competition against the United States.
He won 87 titles worldwide, 50 of them on the European Tour, and had the great satisfaction of captaining Europe to Ryder Cup victory at Valderrama in Spain in 1997.
European Tour chief executive George O'Grady said Ballesteros had been an inspiration as a player and a man.
"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 in a statement.
"We have all been so blessed to live in his era. He was the inspiration behind the European Tour." The tumor was originally discovered after Ballesteros collapsed at Madrid airport in late 2008 and was rushed to a nearby hospital.
He underwent four operations and a course of chemotherapy, appearing in public again for the first time in 2009.
"Today, at 2.10 a.m. Spanish time, Seve Ballesteros passed away peacefully surrounded by his family at his home in Pedrena," the family said on Saturday in a statement on the player's personal website (www.seveballesteros.com).
