Hartsburg will work alongside Flames head coach Brent Sutter.
The two men have a long relationship in hockey. Hartsburg was Sutter's assistant coach on Canada's junior men's team that won gold in 2006.
"I used to just love his intensity and what he stood for, standing behind the bench when he was in front of me," Hartsburg said Monday from Sault Ste. Marie, Ont. "I'm really excited about standing next to him on the bench.
"I have a great deal or respect for Brent and I don't want it to sound like the only reason I'm coming is to work for Brent. I love Brent Sutter, but I'm also excited about working for the whole organization. There's great people there."
The Flames kept only assistant Dave Lowry on the coaching staff at the end of the season, so Sutter was looking for new help behind the bench. The Flames also announced Monday that Jamie Pringle of Picton, Ont., was hired as a video coach.
Hartsburg has been head coach of Chicago, the Anaheim Ducks (1998-2001) and the Ottawa Senators (2008-09). He was also an assistant coach with the Minnesota North Stars and twice with the Philadelphia Flyers during his career.
The 51-year-old from Stratford, Ont., coached in the Western Hockey League the last two seasons, compiling a 74-54-16 record with the Everett Silvertips.
"One of our primary objectives was to enable Brent to select the people in whom he had the most confidence and the personnel he felt would help us achieve the success we strive for in Calgary," Flames general manager Jay Feaster said Monday in a statement.
Hartsburg indicated he wasn't in line for a position as a head coach in the NHL next season, but two other clubs had expressed interest in adding him to their respective staffs.
"I wasn't prepared to wait around," he said. "The things that intrigued me, talking with Brent and Jay . . . the culture and what we're trying to build is important."
Calgary (41-29-12) vaulted from second-last in the NHL's Western Conference in December into the playoff hunt with a strong second half, only to miss the post-season for the second straight year.
Hartsburg also said his decision to come to Calgary wasn't contingent on the title of "associate coach" instead of "assistant coach."
"It was offered by them," Hartsburg said. "It wasn't something I asked for, but it was certainly exciting when they said that was the position.
Hartsburg makes his off-season home in Sault Ste. Marie because he played junior hockey there and also coached the OHL's Greyhounds during his career.
He guided Canada to back-to-back gold medals at the 2007 and 2008 world under-20 men's hockey championship.
He was a league all-star three times during his 10 seasons in the NHL as a defenceman. He participated in the 1981 Stanley Cup final with Minnesota and represented Canada in both the 1981 and 1987 Canada Cups.
Brent Sutter, 48, is an intense coach who always has his game-face on behind the bench. Hartsburg says he won't be afraid to voice his opinion, even if he doesn't agree with Sutter.
"Somebody in my family said 'I don't know who is going to have the biggest scowl, you or him,'" Hartsburg joked. "My wife reminded me 'you are an associate (coach), you don't have to scowl anymore.'"