Metro reports that the wedding was attended by around 125 guests, including the likes of Robert Downey Jr., Tobey Maguire, and Renée Zellweger.
The Walk The Line actress wore a Monique Lhuillier gown for the event.
Witherspoon and Toth began dating in early 2010 following the actress's split from Jake Gyllenhaal, and the pair announced their engagement last December.
Witherspoon was previously married to her Cruel Intentions co-star Ryan Phillippe between 1999 and 2007, and the former couple have two children together.
A representative for the actress was recently forced to deny that Witherspoon was pregnant with her third child.
Witherspoon's new film Water for Elephants, in which she stars opposite Twilight's Robert Pattinson, is due for release in cinemas on April 22.