Ireland was one of four countries to be admitted to the International Organisation of Francophonie (OIF) as an observer, along with fellow EU member Malta, the West African state of Gambia and the US state of Louisiana.
Saudi Arabia also applied to join the 84-member club -- seen mainly as a vehicle for promoting French influence -- but withdrew its application at the last minute after coming under heavy criticism over its human rights record.
Ireland's European Affairs Minister Helen McEntee told AFP that Ireland "was looking beyond Brexit and developing new relationships within Europe and further afield", including Africa, the Middle East, Canada and South America, all of which are represented in the OIF.
"With Brexit, given we'll be the only native English-speaking country in the EU, we need to place greater emphasis on languages," said McEntee, admitting that she herself did "not speak it as well as I should.
She said that joining the OIF was also a way to boost ties with France, which has steadfastly backed Ireland's demand that any Brexit divorce deal avoid creating new barriers between British-controlled Northern Ireland and the Irish Republic.
"That relationship (with France) is strong and this is just another opportunity to strengthen it," she said.
French is currently the world's fifth-most spoken language after Mandarin Chinese, English, Spanish and Arabic, according to official French estimates based on the population of countries where French is an official language.
President Emmanuel Macron is anxious to get more people speaking his native tongue, particularly in Africa, seen as a wellspring of potential new French speakers.
According to the OIF, 12 percent of the Irish and 13 percent of the Maltese are francophone -- more than Moldova, a full member of the OIF where only two percent of the population speak the language.