Scott, 47, had been director of player development for the Blue Jays since Nov. 28, 2001. Scott replaces Al Pedrique, who will be bench coach with the Major League club in 2010.
"Over the past few years, Dick and I have worked together on different committees and always seemed to view player development in the same light," Astros assistant general manager Ricky Bennett said. "With Dick's experience as a player and manager in the Minor Leagues, he'll be a huge asset to our staff as we continue to teach our players how to play the game the right way."
A former infielder, Scott began his coaching career as a Minor League manager in the Oakland Athletics organization in 1991, winning Manager of the Year honors with Class A Scottsdale that season. Scott also received the honor in 1992 and '94, when was also named Minor League Manager of the Year by USA Today Baseball Weekly.
Scott joined the D-backs organization in 1997 as a Minor League manager before becoming a Major League scout for Arizona in 1998, remaining with the D-backs until joining the Blue Jays in 2001.
Originally drafted in the 17th round of the 1981 draft, Scott played 10 seasons within the Yankees and Athletics, including appearances in three Major League games with the A's in 1989.
Brian McTaggart is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.