"ECOFIN has taken final decision approving Latvia's euro membership from 2014," the EU's current Lithuanian presidency announced via its Twitter account.
"Yes we are joining the euro as of January 1 next year," said Prime Minister Valdis Dombrovskis, adding it was "good news not only for Latvia but also for Europe and the eurozone."
Heading into the ECOFIN council's meeting earlier, Latvian Finance Minister Andris Vilks had described it as a "symbolic day".
Asked whether he had any qualms about joining the single currency at such a difficult time, Vilks acknowledged that "those hard times will last several years at least".