The Ravens also have lost cornerback Lardarius Webb for the season.
Baltimore Ravens coach John Harbaugh announced Monday that All-Pro linebacker Ray Lewis is done for the year, according to nfl.com.
"... Ray has a triceps tear. A complete tear. So he'll be out for the season. We just found that out in the last five minutes," Harbaugh said.
Harbaugh also said cornerback Lardarius Webb will miss the rest of the season with a torn anterior cruciate ligament.
Both players were injured in the Ravens' 31-29 victory over the Dallas Cowboys on Sunday.