Kerala United Football Club (formerly Quartz Football Club) is an Indian professional football club based in Malappuram, Kerala.

Founded in 1976 as Calicut Quartz, the club was an amateur and academy side during its early years. In December 2011, they announced intention to turn professional and participated in 2012 I-League 2nd Division, which was then the second tier of Indian club football. The club spent a season in the second division during 2011–12 and later played in the Kerala Premier League. In 2017–18 Kerala Premier League season, they finished as runners-up. They have also competed in the I-League 3.

In 2020, the club underwent a substantial change in ownership as the "United World Group" assumed control. This marked the beginning of a new chapter, accompanied by rebranding of the club as Kerala United FC. The club initially began their training at Seethi Haji Stadium at Edavanna, later moving to Payyanad Stadium.

Founded in 1976 as Quartz Football Club in Kozhikode, Kerala and since has been growing up step by step from district to state to national level. The Quartz Academy was incorporated in 2009. In December 2011, they were officially certified by the All India Football Federation to participate in the I-League 2nd Division. For the first time in 2012 I-League 2nd Division, Quartz FC participated but failed to make an impression. They only got one point in the group stage thereby failing to get promotion.

In 2012–13 season, Quartz FC signed I-League players like Rino Anto, Sabas Saleel, K. Noushad, Manoj Manoharan, Sherin Sam, Kamardeep Singh, Suji Kumar, J. Prasad, P.M. Britto, Salil Usman and Ajmaluddin. Club also signed the top-scorer and player of the tournament at the 2012 Santosh Trophy V.V. Farhad. They appointed Assistant coach Bino George of Chirag United Club Kerala. Later withdrew from the 2013 I-League 2nd Division due to financial instability.

Club managed to win Kozhikode District League back to back in 2011 and 2012. Later in 2013–14, Quartz played with their academy side in the very first edition of Kerala Premier League. After making a late entry in 2017–18 Kerala Premier League season, the club finished as runners-up after losing to Gokulam Kerala in final. They had withdrawn from two editions of Kerala Premier League (2016–17, 2018–19) due to financial issues.

"Kerala is known to be the heart of Indian football and when it comes to passion and support, no fan base in India comes close to their love for the beautiful game. Our focus will be on cementing and strengthening the foundations of the club, building an academy and developing homegrown players."

In November 2020, English Premier League Club Sheffield United have taken over Calicut Quartz and rebranded it as Kerala United FC. United World Group, the umbrella firm holding Sheffield, said in a statement that it envisages to make Kerala United a competitive, community-focused football club playing at the highest level possible in Indian football.