Locked Up (Spanish: Vis a Vis) is a Spanish serial drama television series produced by Globomedia, initially for Spanish Network Antena 3 and later for Fox Spain. It premiered on 20 April 2015. The series focuses on Macarena Ferreiro, who is sent to prison for fiscal offenses and goes on to depict prison life and the corruption of law-enforcement bodies.

One year after Antena 3 cancelled the show, Fox Spain announced they had picked up the series for a third season, which premiered on 23 April 2018. It became the most watched paid TV in its timeslot. A fourth and final series premiered on 3 December 2018. Additionally, Netflix also bought global streaming rights for the show.

Following the show's initial cancellation, several cast members moved on to other projects, resulting in major cast changes in seasons 3 and 4. Production also moved to a different filming location, as the previous studio became the set of another Álex Pina show, Money Heist. Maggie Civantos, who played the series' main character in the first two seasons, had her role reduced due to her commitment to another show, Cable Girls. However, Najwa Nimri, Berta Vázquez, María Isabel Díaz Lago, Marta Aledo, Laura Buena and Alba Flores returned as main cast members.

A spin-off entitled Vis a vis: El oasis was released in 2020, and focuses on Macarena and Zulema, and serves as the last installment of the series.