"We are deeply saddened that our beloved father passed away today", Hawking's children, Lucy, Robert and Tim, said in a statement. He was a great scientist and an extraordinary man whose work and legacy will live on for many years.
India's Prime Minister Narenda Modhi said Hawking's "grit and tenacity" inspired generations of people throughout the world.
A family spokesman said he died peacefully at his home in the city of Cambridge where he worked for decades as the Lucasian Professorship of Mathematics at the University of Cambridge.
Professor Stephen Hawking appeared via hologram to address an audience at the Sydney Opera House in April 2015.
The best-known theoretical physicist of his time, Professor Hawking wrote so lucidly of the mysteries of space, time and black holes that his book, A Brief History of Time, became an global bestseller, making him one of science's biggest celebrities since Albert Einstein. His great discoveries and work include Hawking radiation, Penrose-Hawking theorems, and many more.
The illness gradually robbed him of mobility, leaving him confined to a wheelchair, nearly completely paralysed and unable to speak except through his trademark voice synthesiser.
"I try to lead as normal a life as possible, and not think about my condition, or regret the things it prevents me from doing, which are not that many", he wrote on his website. However, with the use of technology, he was able to communicate without much difficulty.
STEPHEN Hawking was an English-born national treasure - however his computer's voice did leave some puzzled.
A previous holder of the prestigious post was the 17th-century British scientist Isaac Newton.
Hawking himself also guest-starred in many shows including The Big Bang Theory, The Simpsons, Futurama, Alien Planet, Red Dwarf, etc.
Fellow scientists praised Hawking for his contribution to physics.
"Alongside the benefits, AI will also bring dangers, like powerful autonomous weapons, or new ways for the few to oppress the many", Hawking said in 2016, at the opening of a new AI research centre at Cambridge University. He was also wonderfully amusing with a fantastic media savviness that propelled him into A-list celebrity stardom as few other scientists before.
His early life was chronicled in the 2014 film "The Theory of Everything", with Eddie Redmayne winning the best actor Academy Award for his portrayal of the scientist.
"His passing has left an intellectual vacuum in his wake", said Neil deGrasse Tyson.
Former US Ambassador to the UN Samantha Power underlined Hawking's kind heart in addition to his brilliant mind.