Mariappa most recently played club football for Championship side Bristol City in May but spent a large portion of his career in England's top-flight competition playing for Watford, Crystal Palace and Reading.
The 35-year-old from London also made his international debut for Jamaica in 2012, and has since made 57 appearances and captained his country on seven occasions.
"When the opportunity to join the Bulls arrived, it was one I couldn't turn down," Mariappa said.
"It's an exciting new challenge for me in my career and that for me is what I thrive off.
"I'm hungry to achieve great things with the club and create new memories with the team and the fans."
Macarthur have one win and one draw from their opening two matches of the A-League Men season, with centre-back Mariappa to provide further defensive strength.
"I'm thrilled that the club has been able to secure a player of Adrian's quality and experience," coach Ante Milicic said.
"Although he has never played A-League before, I'm most certain he will make a seamless adjustment given the career he has had so far."