Tyler Hubbard, Brian Kelley, Michael Hardy and Mark Holman wrote the song on June 1, 2017, in Austin, Texas, during the first day of FGL's Smooth Tour. Mark Holman had the beat, which the other three thought was cool and when Hubbard had the idea of "simple" they started rolling with it.
Hardy recalled to The Boot
: "With one-word titles like 'Simple,' it's fun to just dial back and think, 'Okay, how simple can we make this lyric?' That's [how we got] the 'One, two, three ... I met you and you met me' kind of stuff. It's just simple. It's fun to dig into those sorts of things when you have a title like that."