Christina Davidson and Frank Tucci, a couple from New Jersey, were selected to exchange vows on the prize presentation.
"To celebrate the message of the song, McBride and Monahan will perform the duet during a very special moment in the show, when a couple will get married live onstage," the network said in a news release.
The song was written by Monahan and originally released in 2010 on his rock band Train's fifth studio album, "Save Me, San Francisco."
McBride, a country music star, covered the song on her latest album, "Eleven."
The ACM Awards show is to take place Sunday at the MGM Grand Garden Arena.