The 22-year-old inked a three-and-a-half-year deal on transfer deadline day and could make his debut against Everton today.
Sylla, who has one Under-21 cap for France, said that he is "excited" to join a club of Villa's magnitude.
"The challenge of joining such a big club as Villa excites me," he told the club's official website. "I have had a great welcome from everybody. I've now met everyone.
"I've seen that things have been difficult here recently, but I want to fight for the club and help the team."
"I am a defensive midfielder, a ball winner. I want to help the team to defend well. That's my aim."
Villa are currently 19th in the table.