Osasuna

The club was founded on 24 October 1920 and its name, Osasuna, meaning health in Basque, was chosen by Benjamín Andoian Martínez. When Spanish football became professional in 1928, Osasuna was placed in the third division, gaining promotion to the Segunda División after the 1931–32 season by winning the playoff against Nacional de Madrid. They made it to La Liga three seasons later. That same season, they reached the semi-finals of the Copa del Rey and lost to Sevilla. The next season , Osasuna reached the semi-finals again, this time losing to Barcelona over two legs, despite grabbing a victory in the first leg.

The club was hit hard by the rearguard repression implemented by the Nationalist rebels in the 1936 coup-de-état against the Spanish Second Republic. At least ten players, employees and directive board members were murdered, imprisoned or otherwise persecuted. The surviving members were forcibly recruited for the front, with some of them showing enthusiasm for the putsch. The strong support of Navarre for the Nationalist rebels led to Osasuna being offered a place in the 1939–40 La Liga when official competitions resumed, although they had finished last in 1935–36 and should have been relegated; ultimately a play-off was arranged with the other demoted team Atlético Aviación – associated with the Spanish Air Force and thus favoured by the military regime. The Madrid team won the tie and, with support from their powerful backers, went on to claim the league title and retain it. It would not be until 1953–54 that Osasuna again participated in the top division, and 1956–57 when they managed to keep their place among the elite, remaining there for three further years.

In September 1967, Osasuna's El Sadar Stadium was opened with a match between Osasuna and Vitoria de Setubal, with the hosts winning 3–0. The club achieved its first ever UEFA Cup qualification in 1985–86 after finishing sixth in the league; their campaign began in the first round, eliminating Scottish club Rangers before being knocked out by Belgian club Waregem 3–2 on aggregate. In the 1990–91 season, Osasuna finished fourth in the league, their best ever league finish until then. This gave them qualification for the following season's UEFA Cup, where the club reached the third round by eliminating Slavia Sofia and Stuttgart. Finishing last in 1993–94, the side spent six years in the second level, before finally being promoted in 1999–2000 after placing 2nd in the league table.

In the 2002–03 Copa del Rey, Osasuna reached the semi-finals for the first time since 1988. The team entered the competition in the Round of 64, where they beat Lemona. In the following rounds, they beat Eibar, Real Unión and Sevilla, until the semi-finals where they were knocked out after losing to Recreativo de Huelva 4–2 on aggregate.

In 2005, they reached the Copa del Rey final for the first time, losing to Real Betis after extra time. They had a tough campaign in that season's Copa Del Rey, almost being eliminated in the round of 64 but narrowly beating Segunda División B side Castellón on penalties after a goalless draw. They went on to beat Girona 1–0 in extra time, then Getafe, Sevilla and Atletico Madrid each by just one goal difference on aggregate to get to the final.

On 27 November 2005, Osasuna played their 1,000th game in La Liga. After a stellar 2005–06 domestic campaign, they made history by finishing in fourth place – equalling the best-ever finish – to enter the qualifying phase for the UEFA Champions League in the following season. This achievement was made more dramatic by the suspense that was maintained until the last day of the championship in which Osasuna and Sevilla were both vying for fourth place – both eventually ended the season with the same number of points but Osasuna finished higher due to their head-to-head record. However, they did not make it to the Champions League group phase, after being eliminated by Hamburger SV in the third qualifying round, leaving the Navarrese to compete in the UEFA Cup for the fifth time.

Osasuna were drawn in Group D of the 2006–07 UEFA Cup, and qualified for the knockout stage after finishing second in the group. In the Round of 32, they and were drawn against Bordeaux, progressing 1–0 on aggregate, drawing 0–0 away before winning 1–0 in Pamplona through an extra time winner by Javad Nekounam. Osasuna's next opponent was Rangers, and Osasuna again progressed following a 1–1 draw in Glasgow and a 1–0 win at home. The club was drawn against German side Bayer Leverkusen in the quarter-finals. Regarded as severe underdogs, Osasuna not only progressed to the semi-finals but did so in style (a 3–0 away win had virtually sealed the tie, but the Rojillos also won the second leg, 1–0). In the semi-finals, the club was drawn against holders and fellow Spanish side Sevilla, eventually losing 1–2 on aggregate after a 1–0 home win.

In the following two seasons, Osasuna struggled heavily in the league. In 2007–08, they finished 17th and only one point above relegation. In 2008–09, they only avoided relegation in the final day; being in 18th place and entering the final matchday at home to Real Madrid, the club fell behind but came back with two goals (the decider courtesy of Juanfran, a Merengue youth graduate) to beat 9-men Los Blancos and remain in the top flight by finishing 15th.

Osasuna had great success in 2011–12, finishing seventh and one place away from qualifying for the European places, but struggled again in the next 2 seasons, finishing 16th in 2012–13 and being relegated to the second division after an 18th-place finish in 2013–14. In the 2014–15 season, the club managed to end up one position above the relegation zone. A managerial change resulted in substantial improvement, and Osasuna won the final match of the regular 2015–16 season 0–5 away to Oviedo, finishing sixth in the table and qualifying for promotion playoffs and. They subsequently won all the playoff games – against Gimnàstic de Tarragona in the semi-final and Girona in the final – to achieve promotion to La Liga once again. Osasuna finished 2016–17 in 19th position, resulting in relegation. They could only manage 8th in their first campaign back in the second tier.^[]

On 20 May 2019, Osasuna achieved promotion back to La Liga after Granada's victory over Albacete, mathematically ensuring a promotion place with three matches left in the season. On 31 May, they defeated Córdoba to finish as 2018–19 Segunda División champions.

The club celebrated its centenary in October 2020 with a league victory over Athletic Bilbao, albeit the match was played in an empty stadium owing to restrictions caused by the COVID-19 pandemic in Spain. In May 2021, after decades of silence and alongside other Navarrese institutions, club president Luis Sabalza paid homage for the first time to the members who went through the rearguard Nationalist repression during the Spanish Civil War, on behalf of the board of directors.

In 2023, having qualified on the field for the UEFA Conference League via a 7th place finish in La Liga (they also reached the 2023 Copa del Rey final, but lost to Real Madrid), Osasuna found itself embroiled in match-fixing allegations dating back to 2013, which led to an initial ban from participating (this being the first occasion they had been eligible for a UEFA competition since the events). The club decided to appeal to the Court of Arbitration for Sport (CAS), who ruled in their favour in deeming that the club was sufficiently distinct from the directors who committed the offences and reinstated their access to the Conference League. UEFA also initiated a disciplinary case against Osasuna for taking the matter to civil courts.