The 30-year-old, who has nine senior international caps for Wales, joined Bath in September on a short-term deal.
The former Newport Gwent Dragons and Biarritz player began his career at Ospreys, and also had a short spell with Cardiff Blues.
"I've really enjoyed getting a good run of games under my belt," Brew told Bath's club website.
Director of rugby Todd Blackadder added: "Aled has brought so much to the team, on and off the field, since his arrival and will continue to form an integral part of the squad."
Bath wing Aled Brew has signed a contract extension with the Premiership club until the end of next season.