The Hills stars got married in an early evening ceremony at the Westminster Presbyterian Church in Pasadena, Calif., on Saturday, PEOPLE has confirmed.
Montag, 22, and Pratt, 25, exchanged vows before about 200 guests, including Audrina Patridge, Kristin Cavallari, Brody Jenner and Frankie Delgado. The bride wore jewels from Neil Lane, including a pear-shaped diamond floral necklace with multiple diamond chains layered over it, diamond earrings and diamond hairpins, which she picked out the day before the nuptials. Pratt borrowed a pair of diamond cufflinks from the jeweler for the big day.
Early Saturday, the couple arrived at the church in a white Rolls Royce Phantom. Before the ceremony, an airplane flew overhead and wrote "Spencer loves Heidi" in the sky. Pratt, looking dapper in a black suit, smiled and signed autographs for fans outside the church.
Meanwhile, Montag posted multiple updates on Twitter throughout the day. "This is going to be the best day of my life," she wrote at one point. "Thank you God for Spencer." She also described her wedding dress as "amazing – like a swan princess."
After the ceremony, the newlyweds emerged and kissed on the church steps. Wedding guests threw rose petals at the couple, who left for the reception in black Rolls Royce Phantom.
Heartfelt ToastsThe night before the ceremony, the couple held a rehearsal dinner at Wolfgang Puck's Beverly Hills restaurant Cut. The dinner included about 40 guests – and camera crews, which filmed the evening's events, including the couple's heartfelt toasts.
The wedding comes five months after the pair flew to Mexico for an impromptu ceremony. The Mexican celebration, which Pratt described at the time as having "margaritas, sunsets and beautiful settings," did not include family and friends.
Next? The couple has joined the cast of the reality show I'm a Celebrity ... Get Me out of Here!, which will premiere June 1.
Reporting by PERNILLA CEDENHEIM, ELIZABETH LEONARD and MONICA RIZZO