The 26-year-old singer discussed the song and his album Heartbreak Weather during Wednesday's at-home episode of the NBC late-night show.
Horan said "Dear Patience" was feeling "very relevant" as people stay home and practice social distancing due to public health concerns about COVID-19.
"I just thought -- it's an album track, but I thought it was really relevant right now because I wrote it at a time when I need to be patient," the singer said. "And if anyone needs to be patient right now, it's all of us."
"This song is basically me writing a letter to the feeling of patience, like, 'C'mon, dude. Let's go for a drink. We haven't spoke in a while.' So, I feel like we can all -- it's very relevant right now. So, we can all pay attention to that," he added.
"Dear Patience" appears on Heartbreak Weather, Horan's second solo album, released this month.
"It was a lot of fun to make. I had a great time making it," Horan said of the album, which he previously described as a concept album about a breakup. "Bit of a shame that I had to release it amongst all this, but you can't win every week."
Horan is isolating at his apartment in London amid the coronavirus outbreak. He performed a live stream concert to help entertain fans last week.
Horan is slated to begin a new leg of his Nice to Meet Ya tour in July.