This is the fourth single from California rock band Train's fifth album, Save Me San Francisco. The song finds the narrator imagining proposing to a girl that he's not even spoken to yet. Vocalist and chief songwriter Pat Monahan explained to PopEater: "The fact that 'Marry Me' is more fantasy than it is 'Hey, marry me.' It's 'What if I did this?' What if I took this chance in this love-at-first-sight moment and said, 'Hey, I know you don't know me and I'm just getting a coffee, but I think that we're supposed to spend the rest of our lives together'? Wouldn't that be incredible? Just because I think that men – I don't know how women work, but men, the ones that I know, we tend to fall in love several times a day – with that woman who gave me that cup of coffee or 'Did you see the producer of the show?' We just are like that, and it's just interesting to think that it's got to be a universal thing among men."
Country star Martina McBride got together with Pat Monahan to record a duet version for her album Eleven. She told Billboard magazine, they initially performed the song during an episode of CMT Crossroads together, "as a duet where people are not really talking in the song, they're dreaming of talking to each other." The singer added that they, "decided to keep it separate and come together at the very end, which was very different for a duet. Usually, you trade lines or sing together throughout the song."
It proved to be a "great moment in the show," so Monahan traveled down to Atlanta to record the song with McBride, "in the studio - face to face, with us singing it at the same time."
McBride and Monahan performed this song at the 2012 ACM Awards in Las Vegas whilst Christina Davidson and Frank Tucci tied the knot on stage. The newly weds originally met under tragic circumstances, both having lost their first spouses in 2009.