The 34-year-old attacker has been a pivotal figure in four Australian World Cup qualifying campaigns and two World Cups, in 2006 and 2010.
Heart coach John Aloisi today said he was thrilled to bring Kewell to the club as he rebuilds the squad for next season, having already added Iain Ramsay and Massimo Murdocca.
“I have been in regular contact with Harry over the past few months and have been so struck and impressed by his hunger,” Aloisi said.
“He has always been a wonderful professional and a winner and, in spending time with him, nothing has changed.
“I watched Harry’s progress in the Middle East very closely and it’s clear that physically he is in great condition so we are confident that, with a big pre-season, he will be flying by round one.
“It’s impossible to argue against the football quality and international experience that Harry will bring to our team and to the Hyundai A-League.
“With the right support, there is absolutely no reason why Harry cannot make a substantial contribution toward the team’s success this season.” 
Kewell said that Melbourne Heart was the perfect fit.
“It’s always been my intention to come back and play in the A-League,” Kewell said.
“John Aloisi and I have known each other a long time and we have played together, so I’m thrilled to be part of Melbourne Heart at an exciting time.”
Melbourne Heart CEO Scott Munn said he was also convinced by the contribution Kewell will make to the team and the club's continued growth.
“Everyone at the club is impressed with Harry’s positive mindset and motivations for coming to Melbourne Heart,” Munn said.
“He is very keen to work with John Aloisi and achieve success alongside him; he absolutely loves the city of Melbourne and, significantly, he has a desire to work closely to develop our younger players.
“Harry is not coming to the club as a marquee player - and will be within the salary cup - but as a player with a lot to prove and some unfinished business.”
Kewell remains an iconic figure within Australian sport; his exploits with the Socceroos, Leeds United and Liverpool making him a household name, and will wear the number 10 jersey for Heart.