Another The Hills star is offically off the market: Heidi Montag's older sister Holly Montag is engaged.

Heidi was the one to break the news of her engagement on Twitter.

"A HUGE congratulations to my amazing loving sister on her engagement to Richie! Answered prayers! love u so much & am so ecstatic for u!" the reality starlet tweeted on Oct. 13.

Holly later tweeted a photo of her gorgeous engagement ring: "Happiest girl in the universe!"

According to Us Weekly, Holly never went public with her relationship with her now-fiance Richie.

Holly appeared in 25 episodes of The Hills alongside Heidi starting in Season 3.

Holly isn't the only Hills star to be lucky in love.

This past weekend, Lauren Conrad announced her engagement to USC law student William Tell - just a day after ex-boyfriend Jason Wahler walked down the aisle and married model Ashley Slack.

Tags: The Hills engagement