The "Gift of Forgiveness" author and the "Guardians of the Galaxy" star -- who tied the knot in 2019 -- welcomed their third baby together, a son named Ford Fitzgerald Schwarzenegger Pratt, on Nov. 8.
"We are overjoyed to announce the birth of our son," they shared on Instagram Nov. 11. "Mama and baby are doing well and Ford's siblings are thrilled by his arrival. We feel so blessed and grateful. Love, Katherine and Chris."
Schwarzenegger confirmed that they were expecting their third baby together in July with an Instagram post featuring her bump and a pair of pink plaid maternity overalls.
Their little one joins big sisters Lyla, 4, and Eloise, 2, as well as Chris' son Jack, 12, with ex-wife Anna Faris. And over the years, the "Jurassic World" actor has given insight into life with his kids.
"They are cute and they're wonderful," Pratt told E! News in May. "They're sweet, polite, kind, joyous little angels, and I love them."
He even made it a goal to raise his children in a way that encourages confidence and self-expression, revealing how his parenting style differs from how he was raised.
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"I think there's a new age of parenting," he continued. "I grew up, I did exactly what my parents said all the time. I never knew I could say 'no' to my parents. And now I'm a guy who didn't have a super healthy grip on his own emotions. So we're trying to raise them in a way that they feel comfortable expressing themselves."
Though at times, the 45-year-old admitted, being a girl dad took some getting used to.
"They've got me wrapped around their finger. It's wild," he told E! in a separate May interview, "I hate to make generalizations based on gender but, in my experience, girls are more emotional. They like to hear stories more than they like to wrestle."
Thankfully, he has leaned on his "amazing" wife of five years for support and showed his gratitude in an adorable 2024 Mother's Day Instagram post.
"Witnessing you be a mom to Lyla and Eloise and a stepmom to Jack makes me fall more and more in love with you every day," he wrote in the caption. "The 24/7 job of scheduling, transporting, loving, nurturing, managing calendars, planning activities, the nutrition, the boundaries, the rules, the patience, the gentleness, the firmness, the wisdom, and grace. It's truly a marvel."
As for Schwarzenegger, the eldest of Maria Shriver and Arnold Schwarzenegger's four kids, she previously revealed that motherhood has impacted her life and her relationship with her own mother in a very meaningful way.
"When I became a mother, I felt like everything in my life had led me right to that baby being put on my chest, and it was perfect," the 34-year-old wrote in a 2021 essay on her mom's website. "Embarking on this new chapter of motherhood allowed for a new blossoming of a part of my relationship with my own mother."
"I have always had an immense amount of respect for my mom, but since becoming a mother myself, my respect and admiration for her is out of this world," Schwarzenegger continued. "I ask her questions every single day, not just about motherhood, but about marriage, work, friendships, parenting and so much more. I know how lucky I am to have her."