Athletic Club "B", officially Bilbao Athletic, is the reserve team of Athletic Club, a football club based in Bilbao, in the autonomous community of Basque Country in Spain. The team currently compete in the Primera Federación – Group 1. Founded in 1964, the team holds home matches at the small stadium attached to the club's training facility at Lezama, holding 3,250 spectators or occasionally at San Mamés Stadium, with its 53,500-seat capacity, for important fixtures.
Reserve teams in Spain play in the same football pyramid as their senior team rather than a separate league. However, reserves cannot play in the same division as their senior team. Therefore, Bilbao Athletic are ineligible for promotion to La Liga. Reserve teams are also no longer permitted to enter the Copa del Rey. In addition, only under-23 players, or under-25 with a professional contract, can switch between senior and reserve teams. In recent years, most of Bilbao Athletic's players have been graduates from the club's youth setup ('cantera') via the feeder team, Basconia. As a result of Athletic's signing policy, only Basque players feature also for the reserve team.
Contents
History
The Bilbao Athletic name was first used in 1938 during the Spanish Civil War, when both La Liga and the Copa del Rey were suspended; most of the top Athletic players had joined the Euzkadi XI, a team put together at the suggestion of José Antonio Aguirre, the president of the Basque Country (and himself a former Athletic Bilbao footballer). Euzkadi went on tour to raise funds for the Basque cause, and also played in the Mexican domestic league. However, at home the Campeonato de Vizcaya had resumed in 1938. With their best players abroad with Euzkadi, Athletic could only field weakened sides and, to avoid possible shameful results damaging the club's reputation, chose to enter under the name Bilbao Athletic (derived from the two clubs that merged in 1903 to become Athletic Bilbao – Bilbao Football Club and Athletic Club). Despite the low expectations, they still won the championship and entered the 1939 Copa del Generalísimo, as the club itself regrouped for a return to normality.
In the 1940s, a reserve team called CD Bilbao played at regional level for a few seasons, but when they had the opportunity of promotion to the third tier, the club opted instead to send players to strengthen its more prestigious local partner Arenas de Getxo.
The name was revived in 1964, when Athletic decided to establish a reserve team with Agustín Gaínza as coach. The new Bilbao Athletic initially played in regional leagues before winning promotion to Tercera División in 1966, under Rafa Iriondo; in 1969 they first reached Segunda División.
In 1983–84, with José Ángel Iribar as coach, and an emerging Julio Salinas as striker, the reserves finished in second place, only trailing Castilla CF; both teams were ineligible for promotion, and Salinas won the Pichichi.
Bilbao Athletic dropped back down to the third level in 1996, but the main squad continued to be nurtured with several players who had spells with the reserves.
After 19 seasons in Segunda División B, Bilbao Athletic returned to the second tier after defeating Cádiz CF 3–1 on aggregate in the promotion playoffs. However, in their campaign in the Segunda they were reliant on the same group, a core squad of 20-year-olds who had never played at such a high level before, and despite battling performances in most of their games, a pattern of narrow defeats led to the team finishing bottom and being relegated back down at the first attempt. Somewhat ironically, the promoted teams that season were CD Leganés whose squad included three players on loan from Athletic who would have been eligible to play for Bilbao Athletic that season, as well as the parent club's local rivals Alavés and Osasuna.
Premier League International Cup
Athletic have competed in the Premier League International Cup – an under-23 tournament with all matches played in England – several times, with most of the players involved drawn from Bilbao Athletic plus some younger additions from Basconia and the Juvenil squads (the rules permit the use of a limited number of overage players, but Athletic do not use them). In 2014–15, 2015–16 and 2016–17 the club qualified from their group but were eliminated in the quarter-finals, while in the 2017–18, 2018–19, 2019–20 and 2023–24 editions, they bowed out at the group stage (they did not enter in 2022–23). They recorded their best progress in the 2024–25 season, reaching the semi-finals before losing to eventual winners Nottingham Forest after extra time.
Background
As farm team:
Club Atlético de Bilbao Amateur (1964–1966)
Bilbao Atlético Club (1966–1972)
Bilbao Athletic Club (1972–1991)
As reserve team:
Athletic Club "B" (1991–2006)
Bilbao Athletic (2006–)
Season to season
As a farm team
As a reserve team
14 seasons in Segunda División
5 seasons in Primera Federación/Primera División RFEF
31 seasons in Segunda División B
1 season in Segunda Federación
10 seasons in Tercera División
2 seasons in Basque regional leagues
Players
Current squad
As of 31 August 2026.
Note: Flags indicate national team as defined under FIFA eligibility rules; some limited exceptions apply. Players may hold more than one non-FIFA nationality.
Reserve team
Note: Flags indicate national team as defined under FIFA eligibility rules; some limited exceptions apply. Players may hold more than one non-FIFA nationality.
Out on loan
Note: Flags indicate national team as defined under FIFA eligibility rules; some limited exceptions apply. Players may hold more than one non-FIFA nationality.
Honours
Segunda División B: 1982–83, 1988–89
Tercera División: 1966–67, 1968–69
1ª Regional league: 1965–66
Segunda Federación: 2023–24
Stadium
For big matches, they use San Mamés, the first team stadium.
Selected coaches
Javier Clemente
Agustín Gaínza
José Ángel Iribar
Rafa Iriondo
Ignacio Izagirre (284 matches)
Iñaki Sáez (290 matches, record)
José Ángel Ziganda (242 matches)
Notable players
Note: This list includes players that have appeared in at least 100 top league games, have reached international status, or both.