Yffiniac is a commune in the Côtes-d'Armor department of Brittany in northwestern France.PopulationInhabitants of Yffiniac are called yffiniacais in French.Personalities Bernard Hinault, the cyclist, was born in Yffiniac in 1954. Roger Flouriot is a writer, he was born in Yffiniac. The cyclist Zéphirin Jégard lived in Yffiniac.