The head coach has been rewarded to leading the Cowboys into the play-offs for the first time since 2009 – they eventually lost 26-21 to the Green Bay Packers in the divisional round.
Garrett coached the Cowboys to 12 regular season wins knowing his deal was due to expire, leading to speculation as to whether owner Jerry Jones would hand him an extension.
With nine more games under his belt, Garrett will become the longest serving coach under Jones??? regime, overtaking the legendary Jimmy Johnson.
Garrett took control of the Cowboys mid-way through the 2010 season, replacing Wade Phillips.
Defensive coordinator Rod Marinelli will also extend his deal by three years and??passing game coordinator Scott Linehan is expected to follow suit.