Alexander Guy Cook (born 23 August 1990) is an English music producer and the head of the UK record label PC Music. Cook released his first solo singles in 2014. He has also collaborated with PC Music artists such as Hannah Diamond, GFOTY, EASYFUN, Danny L Harle and felicita. He formed the one-off project QT with musician Sophie and performance artist Hayden Dunham, producing the 2014 single "Hey QT".

Cook came into the public eye as Charli XCX's creative director and has executively produced her projects: Number 1 Angel, Pop 2, Charli, How I'm Feeling Now, and most recently, Brat. Cook was named #12 in the Dazed 100 for "redefining style and youth culture in 2015 and beyond". Cook released his two debut albums, 7G and Apple, and received the Variety Hitmakers Innovator of The Year Award in 2020. In 2022, he co-produced the song "All Up in Your Mind" from Beyoncé's album Renaissance, which earned him a nomination for the Grammy Award for Album of the Year.

Since founding PC Music in August 2013, Cook's label has represented over 20 artists releasing music within a similar style, in which tropes from mainstream 1990s and 2000s pop music are amplified. This style of exaggerated pop tropes grew to serve as the foundation of the genre hyperpop, which Cook is credited for developing and popularising.