The 42-year-old star made the revelation on his WhoSay social networking account along with a snap of the two kissing in front of a Christmas tree.
“Just asked camila to marry me, merry Christmas,” Fox News quoted him as writing on his WhoSay account.
The How To Lose A Guy In 10 Days star has been dating the 29-year-old Brazilian model since 2007 and the couple has two children together Levi and Vida.
McConaughey, who debuted on the silver screen in 1993’s Dazed and Confused, has starred as a leading man in several romantic comedies over the past decade.
Most recently he appeared in The Lincoln Lawyer.