Stamos, 54, shared the news of his engagement to McHugh, 31, with his 2.2 million Instagram followers with a a gorgeous Disney inspired post.
"I asked...she said yes! ...And we lived happily ever after💍," he captioned a cartoon image of the couple.
McHugh, a model and actress who has appeared in The Vampire Diaries and I Am Legend, began dating Stamos in March 2016.
The Full House alum was previously married to Rebecca Romijn.
Congratulations to the happy couple!