Harbaugh has been the coach of the Ravens for the past 17 years, having a winning record in 15 of them.
The contract extension ensures Harbaugh will hit the 20-year mark as a Raven.
He led the team to a Super Bowl during the 2012 season and has made the playoffs seven of the last eight years.
Baltimore lost to the Buffalo Bills in the AFC Divisional Round of the NFL playoffs this past season following an AFC Championship loss to the Kansas City Chiefs a year prior.
Harbs is currently the second-longest tenured head coach in the NFL behind rival head of the Pittsburgh Steelers, Mike Tomlin (18 years).
The veteran head coach of the Ravens is currently tied with coaching legend Bill Parcels at 14th on the all-time wins list with 172 (regular season), with active head coaches in Sean Payton (Denver Broncos) and Pete Carroll (Las Vegas Raiders) right behind him wth 170.
In 2019, Harbaugh won AP Coach of the Year after the Ravens went 14-2, the best single-season record in franchise history.
Harbaugh also holds the NFL record among head coaches for most playoff road wins (eight).