"One Too Many" is an upbeat song about a man who forgets how lucky he is to have someone he loves. It begins with Urban waking up with a hazy memory after a night of drinking. Though he expresses at the beginning of the song that he needs these nights out, he realizes that when he's at the bar he just misses his partner and should have stayed home with her in the first place.
In an interview with Zane Lowe on Apple Music, Keith Urban explained the song. He said, "It's what I call a reluctant surrender. You're at the bar. You swear to God you're not going to answer that phone. You're not going to make that call. Eventually, you're like, 'Come take me home. I've had one too many.' I know that place really well."
Urban also explained that when he first heard the song, penned by Cleo Tight, Daniel Davidsen, James Norton, Mich Hansen, and Peter Wallevik, he knew he wanted to be part of it. "This is a song that was written by some couple of good friends of mine and they sent it to me. I wrote a lot of songs on this record, but when I got sent this song, I just went, 'Oh, no brainer.' It just spoke to me right away," he said.