The actor popped the question to his longtime girlfriend on Christmas.
“Just asked camila to marry me, merry Christmas,” the 42-year-old star wrote on his WhoSay account.
The post is accompanied by a picture of him and Alves kissing near the Christmas tree, probably taken just after the marriage proposal.
Matthew, 42, and Camila, 29, have been together for five years and have two children together, son Levi, 3, and a little girl, Vida, who turns 2 next month.
In September 2008, the actor gushed to People about Alves, calling her, “the love of my life.”