The couple is ready to tie the knot following a whirlwind romance that saw them fall for each other over the summer and spend plenty of quality time with Pratt's 6-year-old son Jack, reports people.com.
Pratt shared the news in an Instagram post on Monday.
"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 an Instagram photo of himself cuddling up to Schwarzenegger, whose engagement ring was very visible.
The news has come just two days after Pratt, 39, helped Schwarzenegger, 29, move from her Santa Monica, California home.
Pratt and Schwarzenegger were first seen together on Father's Day last year when they had a picnic in the park in Santa Barbara. They were later seen on dates around Los Angeles and outings with Jack in tow.
The engagement comes over a year after Pratt announced his separation from Anna Faris in August 2017 after almost nine years of marriage. This was the first relationship for the star since his divorce.
Pratt and Faris settled their divorce last November.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)