Financial terms were not disclosed, but ESPN reported that Glover received $22.5 million with a signing bonus of $6 million.
Glover was waived by the New Orleans Saints for salary cap purposes, but the Cowboys are more than $10 million under the cap and were able to put together a lucrative deal.
Glover, 27, had a breakout year with 17 sacks in 2000 for the Saints. Although that total was more than halved last year, his eight sacks would have led the Cowboys. Dallas managed just 24 sacks last season as defensive end Greg Ellis led the team with six. In Glover's five seasons in New Orleans, his lowest sack total was 6 1/2 in 1997.
Dallas' top starting defensive tackle, Michael Myers, is an unrestricted free agent, and the other starter, Brandon Noble, is a restricted free agent. Both improved against the run last season as the Cowboys ranked 13th in the league, but were unable to collapse the pocket.
The 6-2, 285-pound Glover will provide that interior pass rush Dallas needs and should ease the pressure on ends Ellis and Ebenezer Ekuban.
Along with adding Glover, the Cowboys have re-signed safety Darren Woodson to a five-year, $20 million contract, handed a six-year, $37 million extension to Pro Bowl guard Larry Allen and signed free agent tight end-long snapper Jeff Robinson.