The "Guardians of the Galaxy" star shared the happy news on Instagram, writing, "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! ??."
Pratt and Schwarzenegger began seeing each other last June after they were introduced by Schwarzenegger’s mother, Maria Shriver.
This will be the second marriage for Pratt who announced his separation from Anna Faris in August of 2017 after being married for nearly nine years.
As The Blast first reported, Pratt and Faris officially settled their divorce in November 2018. They had a prenup in place that called for neither side to pay child or spousal support to the other.