Blackstock and Burleson native Clarkson have been dating for around a year.
After the announcement Kelly folded to the pressure to show off her ring and took to Twitter to share the Johnathan Arndt designed ring.
Brandon is the step son to country superstar Reba McEntire and has two kids already.
Blackstock proposed while Clarkson was preparing for the VH1 Divas show in Los Angeles. No date for the wedding has been announced yet.
The engagement did not come as much of a surprise for the Texan, who told Ellen DeGeneres in November that they “totally love each other” and while not engaged at the time “are totally going to get married.”