Alexis Tsipras: Profile of Greek radical left leader
Greeks made a "brave choice" in voting to reject the terms of an international bailout, says Greece's Prime Minister Alexis Tsipras.
The final result in the referendum was 61.3% "No", against 38.7% who voted "Yes". Turnout was 62.5%.
But European officials and "Yes" supporters have warned the result could see Greece ejected from the eurozone.
Greece's governing Syriza party had campaigned for a "No", saying that the bailout terms were humiliating.
Mr Tsipras said late on Sunday that the Greeks had proved that "democracy won't be blackmailed."
His far-left Syriza party won Greece's general election in January and vowed to renegotiate Greece's bailout, worth €240bn (£179bn; $268bn), to end Greece's "humiliation and pain".
BBC News looks at the background of the young, charismatic leader.
Video produced by Michael Hirst and Sara Barman; photos courtesy of Reuters, AFP and Getty Images