The 28-year-old Mexican announced her decision on her website and will discuss her plans Friday. Ochoa, who has been No. 1 in the world the last three years and won 27 times over the last six years, may well be the best-known athlete in her country who is not a soccer player.
"Lorena Ochoa confirms her retirement from the LPGA, as news reports in some media have said today," her statement said. "The reasons and more details on the matter will be given by Lorena personally in a press conference on Friday in Mexico City. Lorena will share this news of a new stage in her life with her sponsors, family members and friends."
The LPGA told The Associated Press it would not comment until Friday's news conference.
Ochoa is scheduled to play next week in the Tres Marias event in Morelia, west of Mexico City. It was not clear if she would indeed play there or if this month's Kraft Nabisco Championship in California, where she finished fourth in the year's first major, was her finale.
"I'm just crushed," Judy Rankin, a Hall of Famer and television analyst, said upon hearing the news. "We won't get to see her play golf. Mostly, we won't get to see her."
Annika Sorenstam was 37 when she announced her retirement in May 2008, saying she wanted to pursue other interests and start a family. She now has a daughter.
The newspaper Reforma first reported the retirement and said she wanted to concentrate on her family and charities. She was married in December to Andres Conesa, the chief executive of Aeromexico airline. He has three children from a previous marriage.
Ochoa has also talked openly about wanting to have children of her own. Last year she began traveling more, playing less, and had more off-course obligations, which include her charity foundation.
"Personally, it's more important the things that I do outside the golf course," Ochoa said last year before a tournament she hosts in her hometown of Guadalajara. "And that's been my main focus right now."
Her retirement is blow to the LPGA, which has been struggling in a tough economy and has seen its number of tournaments decline in recent years.
Sorenstam was a commanding player, and Ochoa was expected to assume that role although she never quite draw the crowds the way the Swede did.
Ochoa was defined as much by her dominance as her graciousness. Mindful of her heritage, she often would go to the maintenance barn during LPGA Tour events and speak with the workers, many of them from Mexico.
She rose to No. 1 in the world in 2006 by winning six times, and she captured her first major at St. Andrews a year later by winning the Women's British Open. Ochoa's other major was the 2008 Kraft Nabisco Championship, where she took the traditional jump into the pond with her family as a mariachia band serenaded her.
She won her fourth consecutive LPGA Tour player of the year award in 2009, narrowly holding off Jiyai Shin.
In 2006, 2007 and 2008, Ochoa produced 21 titles, but last season she won only three times. She still was honored as the tour player of the year for a fourth consecutive year.
This year she has played four events, with no victories and one finish in the top 10. Ochoa has missed the cut only four times in 172 events as a member of the LPGA, and not since 2005.