The 23-year-old has signed on a season-long loan, with an option to buy.
After spells in France, Switzerland and Belgium, Youan has made the switch to Scotland to join the Hibees. The young striker will look to stretch teams with his natural pace and gives Lee Johnson another option to use upfront or on the left-hand side of a front three.
Youan has First Team experience in the top flight across three different countries, having played in French Ligue 1 with FC Nantes, the Swiss Super League with FC St. Gallen and most recently in the Belgian Jupiler Pro League with KV Mechelen.
The forward also has international experience under his belt, having represented France at U18, U19 and U20 level.
Speaking on the arrival of Youan, manager Lee Johnson said: “We are excited to welcome Élie to Hibs and we are glad he chose us out of numerous clubs who were interested in him.
“Élie is a very versatile forward player with excellent speed and dynamism.
“His attributes will enable us to stretch the game and allow us to open up space for our technically-gifted midfield players.”
Head of Recruitment Ian Gordon added: “We are excited to add a player of Youan’s ability to our squad. He has proven he can score goals across different European leagues and we are confident that he will continue to succeed in Scotland.
“Both his pace and his natural goal-scoring ability impressed us and he will give us another option to use in the forward areas.”