The 46-year-old actress and 43-year-old actor are said to have wed at their Bel Air home Wednesday evening. The couple allegedly told friends and family the party was to celebrate Theroux's birthday.
"Jen and Justin wanted to surprise guests and [they] were certainly surprised," a source told People magazine of the 70-plus people in attendance. Aniston's former Friends co-star Lisa Kudrow, Ellen DeGeneres and Chelsea Handler were among those present.
A large cake with two Muppet-like characters dressed in white was brought to the couple's house, and TMZ also spotted a pastor with a Bible entering the home. The pair had their backyard trees wrapped in lights, and intimate, candle-lit tables prepared for their guests.
Aniston and Theroux have been together since 2011, and got engaged in August 2012. The actress was previously married to Brad Pitt from 2000 to 2005, while Theroux was involved with stylist Heidi Bivens from 1997 to 2011.