The club is one of three founding members of the Primera División that have never been relegated from the top division since its inception in 1929, the others being Real Madrid and Barcelona.

[17] Under his presidency, Athletic and their city rivals Bilbao Football Club reached an agreement to combine the best players of both sides to form a team known as Club Bizcaya, which was created to compete in the 1902 Copa de la Coronación (forerunner of the Copa del Rey which officially began a year later) held in Madrid; Bizcaya returned to Bilbao with the trophy after beating Joan Gamper's FC Barcelona 2–1 in the final.

In 1907, they revived the name Club Vizcaya after entering a combined team with La Union and were beaten in the Copa final.

In 1911, former team captain Alejandro de la Sota, was elected as the 7th president of the club, and he was the driving force behind the construction of the San Mamés Stadium (architect Manuel María Smith), which opened in 1913 and soon became one of the symbols of Athletic's dominance in the 1910s, winning the Copa del Rey three times in a row between 1914 and 1916, with Billy Barnes as coach.

Between 1917 and 1919 the club went through a period of institutional crisis and during that time did not participate in the Copa del Rey, having failed to win the regional tournament which acted as the qualifier.

The star of this team was Pichichi, a prolific goalscorer who scored the first goal at the San Mamés on 21 August 1913[22] and a hat-trick in the 1915 final.

The saying "Con cantera y afición, no hace falta importación" (en: "With home-grown teams and support, there is no need for import"), made sense during these early days.

During the 1940s and early 1950s, the club featured the legendary forward line formed by Rafa Iriondo, Francisco Gárate, Telmo Zarra, José Luis Panizo and Agustín Gaínza, which was nicknamed Segunda delantera histórica (en: Second historic attack); midfielder Nando González and goalkeeper Raimundo Lezama (most unbeaten goalie in LaLiga on 1946-47) also stood out from this team.

The latter is remembered as one of the club's most important achievements because Athletic managed to beat Di Stefano's Real Madrid, which had just won the European Cup and LaLiga, and the Spanish federation also ignored Athletic's request to play in a neutral field and forced the final to be played in Chamartin (Real Madrid stadium).

The classic team lineup was: Carmelo; Orue, Garay, Canito; Mauri, Maguregui, Marcaida; Arteche, Arieta (whom they considered Zarra's successor), Uribe and Gaínza.

Thanks to their league title triumph, the team represented Spain in the 1956 Latin Cup, where they reached the final and lost to AC Milan by a score of 3–1.

The 1960s were dominated by Real Madrid, and Atlético went through a few years of transition in which the only figure that shone was goalkeeper José Ángel Iribar, who became one of the club's greatest legends along with Zarra.

The main stars of this team −in addition to Iribar− were the scorer Fidel Uriarte (winner of a Pichichi Trophy) and the winger Txetxu Rojo.

In 1977, the club reached the final of the UEFA Cup after eliminating teams like AC Milan or FC Barcelona, among others, and only losing on away goals to Juventus.

Months earlier, Goikoetxea had injured Maradona after a hard tackle from behind, from which it took him several weeks to recover, and the Bilbao native was sanctioned with 17 games without playing (although the match referee did not show him any card for this fact).

In 1995, Athletic had signed Joseba Etxeberria from regional rivals Real Sociedad, causing considerable bad feelings between the two clubs.

[33] After star midfielder Javi Martínez moved to FC Bayern Munich, Athletic were eliminated from the 2012–13 Europa League group stage, and were knocked out of the Copa del Rey by Basque club Eibar of the third tier.

Bielsa promoted young defender Aymeric Laporte into the side, while striker Fernando Llorente completed a free transfer to Juventus.

[39] In the first leg of the 2015 Supercopa de España at San Mamés, Athletic defeated Barcelona 4–0, with Aritz Aduriz scoring a hat-trick.

Athletic advanced to the quarter-finals in the Europa League where they were only defeated on penalties by the holders and eventual repeat winners Sevilla FC.

B-team coach Gaizka Garitano took over[47] and oversaw an improvement in results, with the club moving well out of danger and narrowly missing out on a Europa League spot on the last day.

[55] In October 2021, a report from the International Centre for Sports Studies (CIES) showed that Athletic Bilbao and Desna Chernihiv (Ukraine) were the only teams in European continental competitions without foreign players.They ended the season on 10th place.

[58] The second was from 1910, consisting of a red-and-white flag (newly adopted as the shirt colours) with a red square in the top left corner, containing the initials of the club in white.

The third, from 1913, involved the same flag, but in this case shown on a pole wrapped around a football (this is very similar to the Real Sociedad crest still in use today, ignoring the crown of royal patronage).

Later, a young student from Bilbao named Juan Elorduy, who was spending Christmas 1909 in London, was charged by the club to buy 25 new shirts, but was unable to find enough.

In 2011, Athletic released a green, white and red away kit inspired by the Basque flag (this was worn against Atlético Madrid in the 2012 UEFA Europa League final).

In the UEFA Cup and the Copa del Rey of 2004–05, the shirt sported the word "Euskadi" in green with sponsorship from the Basque Government.

[72] This policy was changed in 2008, when Athletic made a deal with the Biscay-based Petronor oil company[73] to wear their logo in exchange for over €2 million.

At present, facilities include, inter alia, five natural grass fields, a gymnasium, a pediment, a medical center and a residence for young players.

Lezama has undergone remodeling since 1995 under the presidency of José María Arrate with the construction of new roads and parking entry and exit able to absorb the large number of vehicles that come every day, and a platform cover bringing greater convenience to fans attending the matches of the youth teams and other youth football teams.