The deal is for a reported three-years.
Boiman, who has spent his previous four seasons in the league with the Tennessee Titans, recorded 28 total tackles last season. He was selected in the 4th round of the 2002 draft out of Notre Dame.
Boiman is the sixth free agent the Cowboys have signed this offseason.
Dallas has also signed OL Kyle Kosier (Detroit), WR Terrell Owens, OL Jason Fabini, LB Akin Ayodele and TE Ryan Hannam (Seattle).
2004: Entered the regular season as Titans' starting left outside linebacker due to Peter Sirmon's season-ending knee injury suffered during training camp. Played in seven games with six starts but was limited due to left knee and right calf injuries. Missed final seven games due to injury. Season totals included 24 tackles, one tackle for loss and one pass defensed.
2003: Boiman saw action in every game for Titans, starting contests at New England (10/5), against Houston (10/12) and Carolina (10/19) in place of Peter Sirmon (back injury). Set career-highs in tackles (55), quarterback sacks (1.5), interceptions (2), starts (3) and tackles for a loss (4). Scored his first NFL touchdown of his career, returning an interception 60-yards for a score at Pittsburgh (9/28). Placed fourth on squad registering 16 tackles on special teams.
2002: Saw action in 16 games, primarily on Titans' special teams where he blocked one punt and set a new team record with 28 special teams tackles, most ever by a Titans player since 1987 when it became a recorded statistic. Played as a reserve outside linebacker on defense, posting six tackles and one forced fumble. Made two or more special teams tackles in 10 of 16 regular season games.