Lasting 20 minutes, the joyous ceremony took place in front of witnesses that included Reese's two children, Renee Zellweger, Salma Hayek, Sean Penn and Scarlett Johannson.
The 35-year-old walked the aisle to Here Comes the Bride, wearing a custom-made Monique Lhuillier dress.
And moments after the couple said "I do", 80 white doves were released.
No pictures have emerged from the occasion because the couple prefer to keep a low-profile.
Following a year-long courtship, Jim, 40, proposed to Reese in December, presenting her with a $250,000 four-carat diamond.
While this is his first marriage, it is her second time down the aisle. She was previously married to Crash actor Ryan Phillipe, who is the father of her children, for eight years.
Reese also dated Brokeback Mountain hunk Jake Gyllenhaal, but they split in 2009.
It's a little princess!