The track is a slow-paced love ballad and shows a softer side to the former Gossip Girl actress.
In the video, Momsen is seen projecting grainy images of herself and a mystery man, while singing: "You don't want me/Like I want you/Like I need you."
'You' is the latest single from The Pretty Reckless's debut album Light It Up, which also features their hit 'Make Me Wanna Die'.
Momsen departed from her role on Gossip Girl last year.
She has said that she has given up on acting and will now focus on her music.
Aside from touring and recording new music, Momsen also recently modelled for Madonna's Material Girl line.
Watch the video for 'You' below: