Barnett, who will take the place of Jeff Bagwell, will be a familiar face for Astros hitters, previously serving as the organization's Minor League hitting coordinator in 2009-10.
"Mike Barnett has done a terrific job for us as our Minor League hitting coordinator, and we think his familiarity with our hitters will be a big plus," Astros general manager Ed Wade said in a team statement. "Aside from that, Mike brings experience, dedication and a solid hitting philosophy to the position.
"When we began interviewing candidates, I made it clear to [manager Brad Mills] that we had to find a guy in whom he had confidence, someone who he knew would come to the park every day with a plan to get the most out of our hitters. The fact that Barney and Millsie worked together in the past was a key factor."
Barnett, one of six candidates the Astros interviewed for the position, has several seasons of experience as a Major League hitting coach, serving in that role for the Blue Jays from 2002 to midway through '05. He also worked with Mills in Boston for a portion of the '05 season, serving as a non-uniformed hitting instructor. He then joined the Royals as their hitting coach from 2006-08.
"It is very exciting to have a hitting coach with the experience, knowledge and expertise that Mike has," Mills said. "We are adding another quality individual to our coaching staff, and someone that has worked with almost every player on the roster at some point in time.
"Having a hitting coach that is not only familiar, but respected by the players, the organization and coaches is a big addition to our staff. I'm obviously thrilled to have Mike as our new hitting coach."
Wade added that the organization will begin looking for a new Minor League hitting coach immediately.
Bailey Stephens is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.