The former world No. 1 and two-time Grand Slam champion has not fully recovered from a cracked rib he suffered in an accident at his home in Sydney earlier this month. He has been slowed by foot surgery since March.
"I have decided to take doctors advice and not play next week as returning too early runs the risk of prolonging my recovery period," Hewitt said in a statement released Thursday by Tennis Australia.
"This is obviously disappointing, but I am taking a longer-term approach," he said.
Hewitt, 24, is the world's second-ranked men's player behind Roger Federer. He now plans to target the grass-court season leading up to Wimbledon in June.
Also withdrawing from the French Open was 30th-ranked Taylor Dent of the United States, who is hobbled by an ankle injury.