Songfacts®:

• "OMG" is a song about the rapturous feelings you have when you are in love. NewJeans describe their surprise and excitement about being so happy. Their friends have yet to meet the guy and are curious about this person who's made them so ecstatic.
• NewJeans member Hanni co-wrote this bouncy fusion of pop, rap, and R&B with David Dawood, Gigi, Ylva Dimberg, and the track's producer Jinsu Park. The song marks Hanni's second NewJeans writing credit, after "Hype Boy" from the group's eponymous debut EP.
  
  "Listening to the demos, personally, I always try to think of a scenario, and paint a picture in my head, and then try to write lyrics that unpack that," Hanni told Rolling Stone regarding her songwriting process. "I find nice, pretty words that are nice to listen to - like, good to the ear - and try to match the melody."
• "OMG" is the title track of NewJeans' first album. ADOR, a subdivision of YG Entertainment, released the record on January 2, 2023.
• The song's music video stars the girls as patients in a psychiatric hospital, along with actor Kim Joo-hun, known for his role in the K-drama It's Okay to Not Be Okay. There's singing, dancing and strange goings on. In the video's last moments, someone types, "Am I the only one uncomfortable with this music video's material? Just show their faces and dance."
• NewJeans debuted the song during their appearance at the Golden Disc Awards on January 7, 2023. The televised awards show opened with a medley by the girl group that ended with "OMG."