The loved-up couple - who started dating in the summer of 2018 - tied the knot during a romantic ceremony in Montecito, California, on Saturday (08.06.19) in front of their close family and friends.
A source told People: "The venue is beautiful. Lots of flowers and greenery everywhere. It's a very romantic setting for a wedding."
The ceremony was attended by Katherine's parents, Arnold Schwarzenegger and Maria Shriver, as well as Chris' six-year-old son Jack.
The insider added: "The whole family took wedding photos, including her parents Maria [Shriver] and Arnold [Schwarzenegger]. Everyone just looked so happy."
Following the ceremony, the guests were treated to cocktails on the lawn, and they were also entertained by a live band.
The source shared: "They are using only local food. It's a lot of fresh vegetables. They didn't want the menu to be too heavy, or rich. It's more of a light summer menu.
"For dessert, there are lighter options as well like raspberries, blueberries and red currant."
Chris, 39, was previously married to fellow Hollywood star Anna Faris, but they separated in July 2017, with Chris announcing the news via his Facebook account.
He wrote at the time: "Anna and I are sad to announce we are legally separating. We tried hard for a long time, and we're really disappointed.
"Our son has two parents who love him very much and for his sake we want to keep this situation as private as possible moving forward."
Following a whirlwind romance, Chris announced his engagement to Katherine on Instagram in January.
He said on the photo-sharing platform: "Sweet Katherine, so happy you said yes! I'm thrilled to be marrying you. Proud to live boldly in faith with you. Here we go! (sic)"