The much-travelled target man has moved to the Heart on a two-year deal, likely completing the striking options at coach John Aloisi's disposal for the coming season
The 30-year-old has signed a two-year deal to link up with Heart and follows the arrivals of attackers Josip Tadic and former Gold Coast United speedster Golgol Mebrahtu.
Macallister has plenty of experience in the A-League, with stints at Central Coast, Wellington and Gold Coast.
He made just four starts for United in season 2011-12 before the demise of the club, and had signed for New South Wales Premier League club Rockdale City Suns in a bid to put himself back in the shop window for A-League clubs.
Macallister had been on trial at new club Western Sydney Wanderers before signing for the Heart.
In 63 A-League matches, he has scored an 15 goals and coach John Aloisi said the former Young Socceroos will be a valuable addition to his squad.
"Dylan is certainly a player who is going to add depth and support to our squad," he said.
"He's a different type of player to the attacking options we currently have up front in that he is a strong physical presence, who is also capable of taking up dangerous positions in the penalty box.
"He has a lot of experience to bring to the club. We played together at the Mariners and I'm looking forward to working with him. I know he is a great character and will certainly allow the younger guys to walk taller."
Macallister, who stands at 193cm, also has experience in Europe's premier competition, when he scored for Icelandic club Breidablik in their Champions League qualifier against Norwegian champions Rosenborg in 2011.