Jennifer Aniston to Tie the Knot With Justin Theroux

It looks like America's sweetheart may finally be getting her happily ever after.

Jennifer Aniston's representatives tell ABC News the 43-year-old star was engaged Friday to screenwriter and actor Justin Theroux.

Theroux popped the question on his birthday.

"Justin Theroux had an amazing birthday on Friday, receiving an extraordinary gift when his girlfriend, Jennifer Aniston, accepted his proposal of marriage," Theroux's rep told People magazine.

The news comes just days after a tabloid report that Aniston, 43, and the 41-year-old actor-screenwriter had broken up, allegedly because she wasn't ready to commit, but Aniston's representative told Wonderwall, "It's once again just another fabrication to sell magazines and has no relationship to reality."

The couple met on the set of their movie "Wanderlust" and reportedly began dating in May of last year.

"Every time she was interviewed about Justin she was extremely happy she was using words like joyful and peaceful. She was just feeling really lucky to have him in her life," said Michelle Tan, People magazine's senior editor.

Theroux, who is best known for his comedic talents, was the screenwriter for "Rock of Ages" and "Tropic Thunder," and had small roles on sitcoms like "Parks and Recreation."

Last June Aniston was coy with ABC's Lara Spencer about the new man in her life.

"Are you happy with the personal area of your life these days?," Spencer asked.

"Yes, I'm very happy. I'm extremely lucky and extremely happy," Aniston replied.

But Aniston hasn't always been so happy. For years, her love life has been tabloid fodder. From her break-ups with actor Vince Vaughn and singer John Mayer, who is eight years her junior, to the devastating revelation in 2005 that her husband, Brad Pitt, was leaving her for his "Mr. and Mrs. Smith" co-star Angelina Jolie.

Aniston had gushed about Pitt a year earlier to Diane Sawyer.

"I can't imagine being with any other human being. I married him because he was the love of my life," Aniston said.

But shortly after the break-up, she told "Vanity Fair" she was lonely, and that some of Pitt's actions lacked a "sensitivity chip."

"After Jennifer Aniston and Brad Pitt's divorce in 2005 we actually saw Jennifer try different relationships with different men, but she seems to have found real happiness with Justin Theroux," Tan said.