Castellon B

Football first appeared in the town in 1911, and after a period of time under the consecutive denominations "Deportivo", "Castalia", "Gimnástico", "Cultural" and "Cervantes", Club Deportivo Castellón was founded on 22 July 1922. After a short period of inactivity in the 1930s (which saw SC de La Plana and Athletic Club Castellón take proeminence of football in the city), the club returned in 1939, already in the second division.

The club featured periodically in the top flight, finishing fifth in 1972–73 and adding a Cup final appearance with a team featuring Vicente del Bosque, who later moved to Real Madrid, serving the club as both a player and coach.

On 29 August 1991, in an extraordinary assembly, the conversion of the club to S.A.D. was approved. The first team had just relegated into division two, and would drop another level to the third three years later, in a spell which would last more than one decade.

In the 2004–05 season, Castellón finished fourth in Segunda B, eventually winning its promotion playoffs (both matches) and achieving a return to the silver category. The club's stint in the division would last five years, as relegation would befall in 2009–10, with the Valencian Community outfit ranking last, 13 points behind the following team.

On 18 July 2011, due to the team not paying its players, Castellón was excluded from the third division, being relegated to the fourth. In June 2017, former player Pablo Hernández became joint owner of the club, leading a consortium alongside Angel Dealbert, businessman Vicente Montesinos and others.

On 21 March 2018, Castellón beat the record of seasonal tickets in the fourth division previously held by Real Oviedo with 12,700, establishing the new record at 12,867. On 24 June 2018, it returned to the third tier after a seven-year absence. On 26 July 2020, Castellón promoted back to second division after 10 years by beating Cornellà in final play off promotion, but they were immediately relegated in the 2020–21 season.

On 5 May 2024, Castellón were promoted back to the second division after three years in the third tier, after Córdoba was defeated by already-relegated Recreativo Granada. In the 2024–25 season they finished in 17th place, narrowly avoiding relegation by two positions. Despite a challenging campaign, the team managed to retain their status in the division. A stronger season followed in 2025–26, as the club finished sixth to take part in the promotion play-offs, losing narrowly to Almería.