Former world number one and two-time major winner Muguruza retires
"The time has come to say goodbye, it has been a long and beautiful career, but I feel the time has come to retire," Muguruza, 30, told a press conference at the Laureus Awards.
"It's a decision that I've been taking little by little."
Muguruza had not competed since January 2023 when she played her last official match at the Lyon Open before taking a break from the sport.
"When I stopped competing, I returned home and I welcomed the break with open arms," said Muguruza who ends her career with 10 singles titles.
"Every day that went by I felt better and I didn't miss the discipline and the difficulty of the life I had before, so it has been a progressive thing."
Muguruza made her WTA main-draw debut in 2012, and reached her first Grand Slam final in 2015 where she was defeated by Serena Williams at Wimbledon.
However she beat the American to claim her first Grand Slam at the French Open in 2016, and then beat Venus Williams in 2017 to win Wimbledon.
Her Paris win made Muguruza the first Spanish woman to lift a Grand Slam trophy since Arantxa Sanchez Vicario triumphed in the French capital in 1998.
When she added Wimbledon to her title collection the following year she became the first Spanish female to triumph at the All England Club since Conchita Martinez in 1994.
Fittingly, it was Martinez who coached her to the title and two months later Muguruza rose to number one in the world.