Manager Buck Showalter announced the news before Monday night's game at Tampa Bay.
"We were hoping to get real lucky today, but I think we all knew where it was headed," Showalter said. "It really wasn't making a whole lot of progress."
Showalter said the team is hopeful that Wieters will be ready for Opening Day next season.
"If not, it's not going to be if, it's going to be when," Showalter said.
Wieters had his ailing elbow examined Monday by Dr. James Andrews and will have Tommy John surgery. He has not played since May 10.
Wieters will have the injured ligament replaced by a tendon from the right wrist. He finishes the season with a .308 batting average, five homers and 18 RBIs in 26 games.
"I feel real confident with the two guys that we have here and the depth we have below," Showalter said.