Psycho (Red Velvet song)

"Psycho" is a song that was recorded by South Korean girl group Red Velvet and was released as the lead single from their first compilation album The ReVe Festival: Finale (2019), which is the third and final installment in the group's album trilogy The ReVe Festival. The song was composed by Andrew "Druski" Scott, Cazzi Opeia, and EJAE; was arranged by the former Druski and long-time SM Entertainment record producer Yoo Young-jin; and the Korean lyrics were written by Kenzie. "Psycho" is an R&B track that incorporates elements of pop, trap and future bass, and is about a couple who are in a complicated romantic relationship. A gothic-themed music video accompanied the single's digital release on December 23, 2019.

"Psycho" received positive reviews from music critics for its "smooth and sultry" delivery and its "haunting", "catchy yet structured" production. Though released at the end of 2019, critics cited the single as one of the best K-pop songs of that year. The song charted at number one in Singapore and in North America, where it was the group's second number-one song on the Billboard World Digital Songs chart and tied them with 2NE1 as the girl groups with the most top-10 entries on the ranking. It peaked at number two in Malaysia and for three consecutive weeks on South Korea's Gaon Digital Chart, giving Red Velvet their 12th domestic top-10 entry. The song also charted at number 10 on the New Zealand Hot Singles chart, and spent one week at number 99 on the component UK Singles Downloads Chart, marking the group's UK chart debut.