Haas, 40, was most recently an Eastern supervisor for the Miami Marlins and has been a longtime scout, including working under current Orioles executive vice president Dan Duquette in Boston.
The Orioles had an opening at national crosschecker after Ron Hopkins left the organization in June.
Haas, a former minor league hitter in the Montreal Expos organization, will be under scouting director Gary Rajsich, for whom he also worked in Boston.
Duquette has known the Haas brothers for decades (and was with the Expos when Matt Haas was originally drafted out of high school). Their father, Eddie, is a former big league player and manager who has been one of Duquette's mentors and closest confidants over the years.
Since taking over last November, Duquette has stressed the importance of strengthening the club's commitment to the annual amateur draft.