“I am very honoured to accept [the captaincy],” Kewell said.
“I think it’s a great responsibility to accept and I’m really looking forward to it.
“I have played under some great captains during my career and I’ve learned from them, so hopefully I can call upon a few things they have done and I can bring that to Melbourne Heart.”
Heart head coach John Aloisi, who has previously played with Kewell for the Australian national team, added: “Over the past two months, Harry has shown the leadership qualities that we’re looking for in a captain.
“He has been a positive influence on and off the pitch with the players; he leads by example, and on the training pitch he sets high standards and he demands that all the players follow.
“So I believe Harry will be a great captain for us this season.”