Mérida Unión Deportiva was the predecessor of CP Mérida, which had been founded in 1912 as Sportiva Emeritense, and eventually came to play in La Liga, disappearing in 2000 due to asphyxiating debts.
Founded in 1990 as Mérida Promesas after the merge of Santa Eulalia and Los Milagros, the club was affiliated to CP Mérida until 2000, changed its named to Unión Deportiva, going on to take Club Polideportivo's place as the main team in the city. Having played mainly in the fourth division as a backup team, it did manage seven presences in the third independently, but returned to Tercera in 2009,[1] where it played until being dissolved and replaced by new creation team Mérida AD.