The 19-year-old, who took Wimbledon by storm by beating then-world number one Rafa Nadal on the way to the quarter-finals, had worked with New Zealander Rea since winning the 2013 Australian Open junior singles title.
Governing body Tennis Australia will continue to have a heavy influence over the prodigy's development, with Davis Cup coach Josh Eagle and Canberra-based academy coach Todd Larkham taking over in a tandem arrangement.
"My desire to be at home more in Canberra, when I am not at tournaments has driven me to make the decision for change within my team," the world number 66 Kyrgios said in a statement.
"Not only is Simon a great coach but he is a great person and I wish him all the best in the next phase of his coaching career."
Kyrgios plays his next tournament at the ATP 1000 in Toronto next month.
(Reporting by Ian Ransom; Editing by John O'Brien)