The trio was surprised with the news Tuesday night during their performance on the Opry. Twenty-year Opry member Vince Gill made an unscheduled appearance, interrupting singer Gary LeVox, bassist Jay DeMarcus and guitarist Joe Don Rooney mid-performance.
The men had tears in their eyes and the crowd gave them a standing ovation.
Rascal Flatts is the top-selling country group of the last decade. The trio joins a recent slate of longtime stars invited to join, including Blake Shelton and The Oak Ridge Boys.
Opry membership is among the highest honors for a country musician. It comes with an ambassador-like commitment to the history of the genre and a requirement to perform at least 10 times a year.