KDAF-TV in Dallas reported that Romo got engaged to girlfriend Candice Crawford. Crawford, a former Miss Missouri, works as a sports reporter at the television station.
According to the station, Romo popped the question while celebrating Crawford's 24th birthday with her family at the restaurant Five Sixty, which overlooks downtown Dallas atop Reunion Tower.
A wedding date has not been announced.
"It's good news, isn't it?" Cowboys interim coach Jason Garrett said before Friday's practice. "I just want to get the initial invite."
Romo, 30, has not played since breaking his collarbone on Oct. 25. He previously dated singer Jessica Simpson and country music superstar Carrie Underwood.
On the TV station's website, Crawford says she has a passion for sports, loves to run, play basketball, cook and go to Cowboys games. She is the younger sister of the actor Chace Crawford, from the television show Gossip Girl.
Tim MacMahon covers the Cowboys for ESPN Dallas. You can follow him on Twitter. Calvin Watkins of ESPNDallas.com and information from the The Associated Press contributed to this report.