Microsoft founder Bill Gates said he will "miss Steve immensely".
"The world rarely sees someone who has had the profound impact Steve has had, the effects of which will be felt for many generations to come. For those of us lucky enough to get to work with him, it's been an insanely great honour," Gates said in a statement.
President Barack Obama also paid tribute to the technology titan.
"Steve was among the greatest of American innovators — brave enough to think differently, bold enough to believe he could change the world, and talented enough to do it."