Lange, who has played for over a decade in the Danish Superliga, with Esbjerg, AGF and OB, will link up with fellow Scandinavian A-League stars, Thomas Sorensen and Morten Nordstrand.
Known as being a hard-working forward, Lange is reportedly willing to turn down more lucrative offers from Asia and Germany to join the A-League.
"I am able to play in several formations and I have a reputation as a player of never, ever giving in. Defenders will learn that," Lange told Goal Australia.
Lange was a former teammate of Newcastle Jets attacker Nordstrand at AGF, the current home of Australia's Mustafa Amini, and has scored 48 goals in 245 Danish Superliga appearances.
The 30 year-old also has 10 caps for Denmark Under-21s, yielding a solitary goal in the process.