Reese Witherspoon, 35, is due to get married to talent agent Jim Toth, 40, on Saturday in Ojai, California, reports People magazine.
The couple's A-list wedding guests have been arriving all day and so far, Renee Zellweger, Robert Downey Jr. and Salma Hayek have been spotted at the at the Ojai Inn and Spa, where most of the guests are staying. A rehearsal dinner was reportedly held on Friday night at Witherspoon's Ojai estate.
It was announced earlier in the month that the actress' wedding dress would be designed by Monique L'huillier, but the actress never confirmed the report.
The two have been dating for about a year. This will mark the second marriage for the actress, who was married to actor Ryan Phillippe, 36, between 1999 and 2008.
Witherspoon bought her Ojai Libbey Ranch, which was designed by architect Wallace Neff for $5.8 million (down from the $6.9 million asking price) in 2008.
Witherspoon and Toth were first linked together in January, not long after she and actor Jake Gyllenhaal confirmed they had broken up after dating for about three years. Witherspoon and Toth fended off engagement rumors in October.
Witherspoon is known for movies such as "Legally Blonde" and won an Oscar for the 2005 film "Walk the Line." She recently filmed the movies "Water for Elephants" with "Twilight" actor Robert Pattinson and "This Means War" with Chris Pine and E! talk show host Chelsea Handler.