Polls closed at 16:00 GMT (7pm local)
There will be no exit polls, due to unreliable results in past
Complete result expected by 18:00 GMT (9pm local)
Final result may be delayed slightly if the referendum appears close (it likely will be)
PM Alexis Tspiras to speak as soon as there is a decisive result
Voting has ended in a crucial referendum that will decide whether or not Greeks choose to accept international creditors' proposals for more austerity in exchange for rescue loans needed to avoid default and a banking collapse.
Polling booths closed at 16:00 GMT on Sunday, with opinion polls showing the nation evenly split between "Yes" and "No" vote.
With 10 million Greeks eligible to vote, initial polls broadcast after polling stations closed suggested a narrow win for the "No" vote.
German Chancellor Angela Merkel and French President Francois Hollande announced after the voting had ended that they would meet in Paris on Monday evening to discuss the result.
Prime Minister Alexis Tsipras earlier urged people to vote "No," saying it would strengthen his left-wing government's hand in talks with international creditors who are owed billions of euros.
Tsipras remained steadfast after casting his vote at a polling station in Athens on Sunday morning.
"No one can ignore the message of determination of a people taking its destiny in its own hands," he told reporters.
Finance Minister Yanis Varoufakis has also cast his ballot, telling Germany's Bild newspaper that he will resign if Greeks vote "yes" for the aid-for-reforms package, reiterating comments he has made before.
Asked if he would really resign if the outcome of the referendum was "yes," he told Bild: "Absolutely."
"There will not be a majority for 'yes'," he added.
On Friday, more than 25,000 people welcomed Tsipras at a rally in Athens where he sought to revive support for the "No" vote.
A rival rally of 22,000 "Yes" supporters shouted pro-European slogans and voiced fears of a so-called "Grexit" from the eurozone and a return to Greece's former currency, the drachma, if Tsipras got his way.
Opinion: Greece and the passing of the nation state
| Referendum question:
Should the draft agreement, submitted by the European Commission, the European Central Bank and the International Monetary Fund to the Eurogroup of 25/6/2015, consisting of two parts that constitute their proposal be accepted?
The two documents that form the creditors' proposal:
- "Reforms for the Completion of the Current Program and Beyond", and
- "Preliminary Debt Sustainability Analysis"
In an opinion poll released on Friday, Greeks were almost evenly split over the referendum, with 41.5 percent saying they will vote in favour of accepting the latest bailout proposals and 40.2 percent saying they will vote "No".
The poll showed that 10.9 percent remained undecided, while the rest said they would abstain or leave their ballots blank.
After failing to reach a deal with its creditors last weekend on an extension of its bailout programme, Greece's ruling Syriza government closed the country's banks and imposed capital controls until July 6.
The cash-strapped nation defaulted on an IMF payment of $1.8bn on June 30.
There have been rallies in several European cities, including Dublin and Istanbul, in support of the Greek government ahead of the key vote.
Hundreds of demonstrators marched in the Portuguese capital, Lisbon, to show their solidarity with Athens' efforts to fight the proposed austerity measures.
Portugal, like Greece, had to ask for an international bailout in 2011 to avoid bankruptcy.
After two bailouts totalling 240bn euros ($266bn) and six years of depression, spending cuts and lost jobs, Greece teeters on the edge of collapse.
AL JAZEERA EXPLAINS: One Minute Greek Debt Crisis
Tsipras says the vote is needed to force creditors to finally accept his key demand of another round of debt relief to save Greece from financial meltdown and possible exit from the euro.
EU leaders have warned that a "No" victory could cause Greece to crash out of the eurozone.
"If they [the Greeks] say 'No', they will have to introduce another currency after the referendum because the euro is not available as a means of payment," Martin Schulz, the president of the European parliament, said in remarks broadcast on Germany's Deutschlandfunk radio on Sunday.
European Commission chief Jean-Claude Juncker warned in Brussels that Greece's negotiating position would be "dramatically weakened" in the event of a "No" - and still difficult even in the event of a "Yes" vote.
But Tsipras and Varoufakis have accused them of scaremongering.
In an interview published on Saturday, Varoufakis accused international creditors of "terrorism" .
"What Brussels and the troika want today is for the "Yes" [vote] to win so they could humiliate the Greeks," Varoufakis told the Spanish El Mundo daily.
FIELD NOTES FROM OUR CORRESPONDENT
Athens, Greece - Much is at stake here for Greece, including whether banks will reopen this week as announced, or whether the country will be forced to dip into savings in order to prop itself up.
We don't know if the government will receive another financial aid package and we don't know what the fate of the private sector will be.
|Al Jazeera's Greece correspondent John Psaropoulos in Athens
All of this comes down to a simple "No" or "Yes" vote in today's referendum.
The ballot simply asks: Do you accept the package of reforms submitted by creditors on June 25 and the debt sustainability analysis that goes with it? That is all.
There is a lot of domestic politics riding on those two answers.
In reality, the Greeks are not going to be voting on the specifics, they are going to be voting on their emotions and what they have been through over the past six years.
The referendum is going to be a very blunt instrument for this voting public to express their broader hopes for the future.
Source: Al Jazeera and agencies