"KLK" is a song recorded by Venezuelan musician Arca featuring vocals by Spanish new flamenco singer Rosalía. Written by both of the performers in Barcelona, Spain, the track was released on 22 June 2020 through XL Recordings and Columbia Records as the fourth single off Arca's fourth studio album Kick I.

Rosalia Vila Tobella, known mononymously as Rosalía, is a Spanish singer, songwriter, producer, and musician. Born and raised on the outskirts of Barcelona, she has been described as an "atypical pop star" due to her genre-bending musical styles. After being enthralled by Spanish folk music at age 14, she studied musicology at Catalonia College of Music while also performing at musical bars and weddings.