"Who's That?" arrives as The War On Drugs' first new music since their 2021 album I Don't Live Here Anymore, also following their 2024 live album . The track was written and produced by band leader Adam Granduciel at his Burbank studio compound, and arrives alongside a music video directed by Max Flick.

“'' was written in 10 minutes somewhere between first coffee and school drop off,” Granduciel explains. “It’s a song about trying to love yourself despite things we can’t always control, like the anxiety, depression and self-doubt that may stand in the way of living the life we truly desire.”