The actor, who played Cameron Tucker on the hit sitcom, popped the question to his girlfriend Lindsay Schweitzer at the weekend.
Stonestreet, 49, announced the news on Instagram this morning. He posted several photos of Schweitzer and joked in the caption: "She said,'She'd have her people call my people.'"
Stonestreet and Schweitzer, who is a nurse, have been dating since 2018.
Not long after they got together, Stonestreet raved about his girlfriend on The Ellen DeGeneres Show, saying: "She calms me, she calms my nerves. I'm a very highly strung person."
Stonestreet was previously rumoured to be dating Charlize Theron, but in 2012 he told Extra TV there was no truth to the story.
"We've met a couple of times and hung out at a party," he said. "We took one picture and all of a sudden … [the rumours began].
"I feel like it's a practical joke on me. It's so funny."
