Deadline / REX / Shutterstock / Rex USA 1 / 7
Deadline / REX / Shutterstock / Rex USA 1 / 7

Brie Larson is officially off the market.

The 26-year-old Oscar-winning actress is engaged to her boyfriend, musician Alex Greenwald, her rep confirms to ET.

Larson wore her shiny new engagement ring during hosting Saturday Night Live over the weekend, and Greenwald accompanied her to the after-party in New York City.

"The Room" actress has been dating the 36-year-old former Phantom Planet frontman since 2013. At the 2016 Screen Actors Guild Award in January, Larson sweetly offered up an "I Love You" to her beau during her acceptance speech for Outstanding Performance by a Female Actor in a Leading Role.

"Oh man, I mean, he's the other half of the equation -- how can you explain support?" she exclusively gushed to ET about Greenwald backstage. "I mean, it goes beyond anything. He's just my person, he's my best friend."

"Yeah, we love each other," she added.