The deal ends 50 years of conflict that left hundreds of thousands of people dead and millions displaced.
A ceasefire began on Monday but the deal must still clear two hurdles before it is formally ratified.
President Juan Manuel Santos called this "perhaps the most important announcement" of his life.
He said: "Peace will be signed on 26 September in [the Colombian city of] Cartagena."
There had been speculation that the deal would be signed at the UN headquarters in New York.
Colombians will vote on the deal in a referendum in October before it is fully made into law.
At least 13% of people have to answer "yes" to the question: "Do you support the final accord to end the conflict and build a stable and lasting peace?"
The Farc group, which is on US and European lists of terrorist organisations, will hold a separate vote at a national conference.
Other groups in the armed conflict have not been part of these peace talks.
BBC News |
