Here is some of the tributes which have been paid to the golf legend.
"It's a sad day, lost an inspiration, genius, role model, hero and friend. Seve made European golf what it is today. RIP Seve." - world number one Lee Westwood.
"America had Jack Nicklaus and Arnold Palmer - Seve was our Arnold Palmer and Jack Nicklaus rolled into one. You can't speak too highly of him, Seve was Europe's best ever player." - Bernard Gallacher, who captained Ballesteros in three Ryder Cups.
"We are looking at a top artist - the king of European golf, if you like, for many years. He brought excitement into the European game as Arnold Palmer did into the American game. Everybody drew another breath when he played - it was like watching a masterpiece." - former Ryder Cup team-mate Howard Clark.
"We have all been so blessed to live in his era. He was the inspiration behind The European Tour." - tour chief executive George O'Grady.
"(He was) an absolute gentleman, the ultimate warrior. There's not many players I've worked for in my time that have that aura about them." - Ballesteros' former caddie Billy Foster.
"He was a game-changer. To come from where he did and do what he did was amazing." - fellow Spaniard Sergio Garcia.
"He is the great icon of Spanish golf, one of the biggest characters in the sport in general, both inside and outside our borders, a genuine legend who changed the conception of our sport." - Gonzaga Escauriaza, president of the RFEF (Spanish golf federation).
"He was the guy I wanted to play a practice round with the most. To me the greatest thing about Seve is his flair and his charisma. Because of the way he played the game of golf you were drawn to him. You wanted to go watch him play." - Phil Mickelson.
"He really blazed the trail for Europeans. Not only in the Ryder Cup, but also in how he played at Augusta and his victories over here. We owe a huge amount to him." - Paul Casey.
"He was an icon in the game. Everybody wanted to be as exciting and fun and flashy as Seve - maybe hit a few more fairways, but everybody wanted that style." - new USA Ryder Cup captain Davis Love.
"Seve was a great champion. He was a swashbuckling man, a handsome man who really entertained the crowd." - Julian Small, chief executive of Wentworth Golf Club.
"Seve was a hero to many for all he achieved during his career, but never more so than in the months after he was diagnosed with a brain tumour. His personal battle against the disease, and his determination to help others through his Foundation, was truly inspirational." - Cancer Research UK chief executive Harpal Kumar.
"(He was) one of the greats of this country without a doubt, a reference point for all Spanish athletes." - tennis' world number one Rafael Nadal.
"Not many can say they made the sport they played trendy, cool, fun and sexy. Seve single-handedly did that." - former England cricket captain Michael Vaughan.