Carlisle made the announcement after a 101-78 loss to the Chicago Bulls on Wednesday night.
"We need help at point guard," Carlisle said. "I found out ... that [Darren] Collison would be out, and we were fortunate to get [Jared] Cunningham active. We feel [Fisher] can help us. It's not a cure-all to all of our team challenges, but his expertise and experience will help."
Third-year guard Dominique Jones started for the second consecutive game, finishing with 10 points and five assists.
The 38-year-old Fisher played for the Lakers and Oklahoma City Thunder last season, when he was traded to Houston in the deal that brought power forward-center Jordan Hill to Los Angeles. Fisher took a buyout in Houston and later signed with the Thunder, who won the Western Conference.
The Mavericks, who have played the entire season without All-Star forward Dirk Nowitzki, currently have 15 players under contract, so Dallas will have to release someone to make room on its roster for Fisher.