"I'm so happy for you both!!" Faris commented on Pratt's engagement announcement. "Congratulations!"
Faris and Pratt officially divorced in October 2018, more than a year after announcing their separation. The two have remained close for the sake of their 6-year-old son, Jack, and have even double dated in the past with Schwarzenegger and Faris' boyfriend Michael Barrett.
Other famous friends also wished the happy couple well, including Schwarzenegger's brother, Patrick Schwarzenegger, her mother, Shriver, Avengers: Infinity War actor Tom Holland, Spy Kids star Alexa Vega, Parks and Recreation actor Ben Schwartz, Josh Gad, Parks and Rec star Rob Lowe, Olivia Munn, Gwyneth Paltrow, Quest Love, and many more.
"Love you brother," Patrick wrote.
"Congratulations to two loving kind caring thoughtful Spiritual people we are so happy for you you are blessed as is everyone who knows you yes let's go," Shriver wrote.
"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!" he captioned a photo of himself and Schwarzenegger, whose hefty engagement ring was front and center.
Pratt, 39, had just recently helped Schwarzenegger, 29, move out of her Santa Monica home.
The two were first spotted together out on a picnic date in Santa Monica in June; from then on, they spent much time together, including at church with Jack and out to eat with Schwarzenegger's family. In fact, Pratt even spent Thanksgiving with the Schwarzeneggers; Katherine's mother, journalist Maria Shriver, who filed for divorce from Katherine's father Arnold Schwarzenegger in 2011, reportedly set them up to begin with.
On Shwarzenegger's 29th birthday, Pratt gushed over his fiancée-to-be. "Happy Birthday Chief! Your smile lights up the room. I've cherished our time together. Thrilled God put you in my life," he captioned a collage of photos. "Thankful for the laughs, kisses, talks, hikes, love and care."
The relationship grew serious quite quickly, sources say.
"They're both serious about the relationship and hopeful for the future," a source close to the couple recently told PEOPLE. "Chris doesn't just date to date, and neither does Katherine. She's very excited."
"Chris and Katherine are very happy together," the insider continued. "They're very compatible and have a lot in common."
Meanwhile, Faris and Barrett, a cinematographer, have been dating since November 2017.0comments
Amid their new relationships, Pratt and Faris are committed to co-parenting.
"Chris is dedicated to co-parenting and he's a huge support to Anna," a source told Entertainment Tonight. "Their break wasn't easy and they both want to be the best parents they can be. Chris is dedicated to juggling career, family and Katherine."