Rachel Uchitel - best known as Tiger Woods' mistress #1 - is checking into Celebrity Rehab, RadarOnline.com has learned.

Uchitel, 35, will appear on the fourth season of VH1's Celebrity Rehab with Dr. Drew. Uchitel, a New York party planner, will be treated for an addiction to pills, according to the New York Post who cited a network source.

The paper says the source did not specify what kind of pills Uchitel has an addiction to, although, as RadarOnline.com has previously reported, Uchitel was known to have taken the sleeping pill Ambien with Tiger while they had sex.

Former Tiger Woods mistress Rachel Uchitel and her new hubby Matt Hahn are the proud new parents of a baby girl named Wyatt Lilly, Matt posted to his Facebook page Wednesday.

The baby weighed in at just more than 7 pounds, and “both Rachel and baby are resting comfortably,” according to Rachel's spokesperson.

Former Tiger Woods’ mistress Rachel Uchitel announced Tuesday she’s five months pregnant, tweeting pics of she and new hubby Matt Hahn embracing, with a baby bump in full view.

The New York native tweeted, "Expecting big things for 2012... Five down, Four months to go..." and "checking out my baby bump at 5 months..."

After marrying Hahn in October, Uchitel told us exclusively last month that “a baby is the plan,” adding she doesn’t care if she has a boy or a girl, as long as the child is healthy.

Dog is a bikini babe’s best friend!

Hollywood’s hottest stars love their pooches almost as much as we love their stripped-down bikini bodies.  RadarOnline.com has photos of the most bombshell bikini babes on the beach, showing off their canine pals in this special feature.

PHOTOS: Sexy Bikini Babes And Their Dogs Hit The Beach

Catch it if you can! Life’s a beach for Charlize Theron and her lucky entourage of animals. The flawlessly figured Academy Award winning bikini babe stays in tip-top shape playing ball with her canines, who come in all sizes and breeds.

Tiger who?

Honeymoon hottie Rachel Uchitel is a million miles away from the 2009 Thanksgiving that propelled her to international infamy, and RadarOnline.com has an exclusive interview with the newlywed beauty.

Rocking a green bikini as she finished up a luxurious vacation in the $1,800-a-night presidential suite at the Villa del Palmar at the Islands of Loreto with her new hubby, Matt Hahn, Rachel is happier than she’s ever been, dishing on married life, baby plans and how Dr. Drew Pinsky changed her life.

“Marriage is great,” she said about her two month union. “It is no different than it was before we were married. It feels right and that is how it should be.”

Eat your heart out Tiger Woods!

Rachel Uchitel hit the waves on her honeymoon Sunday rocking a tiny string bikini and RadarOnline.com has the shot of the gorgeous newlywed in Mexico.

With her new hubby Matt Hahn, Rachel is vacationing at the luxury Mexican resort Villa del Palmar at the Islands of Loreto.

Tiger Woods is making headlines for his golf play, once again.

The sports legend wrestled away the lead at the Australian Open Thursday, nailing five birdies in his first nine holes to best Aussie Peter O'Malley by a stroke at the competition's halfway mark.

Woods said he's "playing properly" approaching the two-year anniversary of his Thanksgiving blow-up with now ex-wife Elin Nordegren, which made worldwide headlines, along with the serial-cheating revelations that followed.

Actor David Boreanaz says admitting his affair with Rachel Uchitel made for "a bonding experience, in the long run" with his wife, one-time Playboy Playmate Jaime Bergman.

"In a sacred ground like marriage, you find yourself out of it at certain times for reasons unknown that can be destructive," the strapping star of Bones, Buffy the Vampire Slayer and Angel told TV Week. "There could be a demon that kind of comes out and overtakes you.”

Of his marriage, Boreanaz said, "Do I believe in giving up? No, I don't. I'm a fighter. I'm a lover."

We’ve got a look back at the life of Apple co-founder Steve Jobs, who passed away at 56 this week after a valiant battle against cancer.

Pippa Middleton and boyfriend Alex Loudon were seen at Boodles Boxing Ball.

Riley Keough, Elvis Presley's granddaughter, was snapped on the set of Magic Mike.

Lindsay Lohan attends the DW by Kanye West Show.

Amanda Knox cries as her murder conviction is overturned by an Italian court; she was freed from prison, and returned to the U.S.

Eighties legend Axl Rose, looking worse for wear, arrives at the airport in Rio De Janeiro, Brazil.

Courtney Stodden, 17, and Doug Hutchinson, 51, are happy as can be while spending the day at a resort north of Los Angeles.

Funnyman Seth Rogen marries Lauren Miller in an outdoor ceremony in Sonoma, Calif.

Kendall Jenner is all grown up in her latest modeling photo shoot, posing for the White Sands Spring/Summer 2012 collection while in New York for fashion week.

Rachel Uchitel marries her boyfriend, Matt Hahn, in a secret ceremony in Las Vegas.