A former England Students captain, the 22-year-old forward is a product of the Fylde club in Lancashire.
Before joining Leicester, De Carpentier completed a degree in sports coaching at the University of Wales Institute in Cardiff, during which time he also played in the Welsh leagues.
De Carpentier trained at Sixways during a trial period last month and impressed when he featured for Worcester Cavaliers in the Aviva A League defeat to Newcastle Falcons.
After securing the signature of the flanker, Warriors Assistant Head Coach Nigel Redman said: "Richard has done incredibly well since joining us on trial in October.
"He played out here against Newcastle and did exceptionally well and he's made a massive impact in training. He offers a lot of quality and players get on with him.
"Richard will start his first game for us on Saturday against Scarlets so he's got an opportunity to impress. He gives us another option in the back row and his presence will no doubt drive our standards upwards."