It's a controversial and long-running dispute that has derailed attempts by FYR Macedonia to join the EU and NATO.
But what's it all about and why does it incite such strong reactions in both Greece and the Former Yugoslav Republic of Macedonia?
What’s the dispute about?
FYR Macedonia is controversial for Greeks because it uses the same name as a neighbouring region in northern Greece.
Athens claims the region Macedonia — which is coloured yellow in the map above and lies just across the border from FYR Macedonia — has used the name since the times of Alexander the Great.
There are also concerns that agreeing to FYR Macedonia would lead to Skopje having territorial claims on the region of Macedonia.
How did the dispute come about?
The name dispute was an issue between Belgrade and Athens before the 1990s, when the People's Republic of Macedonia made up part of Yugoslavia.
But it really came to prominence in 1991 when FYR Macedonia declared its independence from Yugoslavia.
Why is the issue in the news?
Greece and FYR Macedonia reached an agreement in June to rename the country the Republic of Northern Macedonia.
But while the prime ministers of both countries were all smiles as they signed off on the deal, there is still significant opposition.
That is reflected by the fact the issue will go to a referendum in FYR Macedonia on Sunday, September 30.
The electorate will be asked: "Are you in favour of NATO and EU membership, and accepting the name agreement between the republic of Macedonia and Greece."
What prompted the deal?
The election last year of FYR Macedonia's pro-EU prime minister, Zoran Zaev, has helped push the issue towards resolution after years of stalemate.
Who opposes the deal?
Apart from the September 30 referendum, there are other key obstacles to the Athens-Skopje agreement.
FYR Macedonia's president, Gjorge Ivanov, has said he won't sign it.
But the country's parliament has twice voted in favour of the deal and Ivanov cannot veto it indefinitely.
Greece's parliament must also ratify the settlement and there have been demonstrations by nationalists who oppose it.