In both sports, Lanús plays in Argentina's top divisions: Primera División (football) and Liga Nacional de Básquet (basketball).

Domestic football major titles won by the club include two Primera División championships, the Copa Bicentenario and one Supercopa Argentina.

Apart from football, Lanús hosts many other sports such as athletics, gymnastics, martial arts, handball, field hockey, roller skating, swimming, tennis, volleyball, and weightlifting.

[6] The club began to play its matches in División Intermedia (the second division of Argentine football league system by then) at Lanús United old stadium, located in Margarita Wield and General Deheza streets.

In the first division, Lanús played its first games in the official association, then switching to dissident Asociación Amateurs de Football (AAmF), where the team joined on 8 August 1920, when the squad was defeated by Racing Club by 1–0.

The stadium (with wood stands as it was usual for that time) was built on a 50,000 m2 land given by the British-owned company Buenos Aires Great Southern Railway ("Ferrocarril del Sud".

Lanús did not make a good campaign, finishing penultimate achieving only 22 points, 28 less than champion Boca Juniors.

With still 1 fixture to play, Lanús won the championship when the team defeated Argentinos Juniors by 3–1 therefore promoting to Primera División.

The team achieved large victories over El Porvenir (5–1), Colón (4–2), Temperley (4–1 and 4–0), Argentinos Juniors (4–0), Unión de Santa Fe (6–1) and Nueva Chicago (6–1).

[11] The line-up for the game that set up the return to Primera was: Alvarez Vega; Daponte, Mercado; Vargas, Strembel, Vivas; Contreras, Gil, Pairoux, Florio, Moyano.

Forward José Florio was the top scorer with 21 goals, having been sold to Italian club Torino for a record $ 1,500,000.

Due to an outstanding line of forwards (that scored 49 goals in 30 games) and their skills with the ball, that squad was nicknamed The Globetrotters honoring the famous basketball team.

The usual team was Vega; Prato, Beltrán; Daponte, Hector Guidi, Nazionale; Carranza, Lugo, Alfredo Rojas, Urbano Reynoso, Moyano.

The Globetrotters thrashed their rivals with large victories over Argentinos Juniors (4–0), Gimnasia y Esgrima La Plata (5–3), San Lorenzo (4–0) and Huracán (4–2).

River Plate squad had players with less individual skills than Lanús', but they were more experienced and those qualities helped them to get the championship at the end of the season.

The two forwards of the team, Manuel Silva and Bernardo Acosta, soon got recognition due to the famous "wall pass" they did together, being nicknamed "Los Albañiles" ("The Construction Workers).

[17] Unfortunately for the club, the tenure of Lanús on 1972 Primera División season was the worst in its history, being relegated again at the end of the championship.

In the second leg, played in Independiente's stadium, the referee gave Racing Club a controversial penalty kick after disallowing a Lanús goal.

The line-up for the final was Ojeda, Gómez, Agüero, Mainardi, González; H. Enrique, Kuzemka, Schurrer, Angelello; Gambier, Villagrán, with Russo as manager.

The good campaign of the team during the 1993 Apertura allowed it to qualify for the Copa CONMEBOL, where Lanús participated for the first time in an international tournament.

On 1 October, Ariel Ibagaza made his debut for the team, where he and Hugo Morales formed a midfield duo highly praised by Lanús' fans.

The line-up for the final match was: Roa; Serrizuela, Falaschi, Siviero, Bresen; Mena, Cravero, Ibagaza, Coyette; Enría, Ariel López.

[19] With Mario Gómez as head coach, Lanús also reached the cup final in 1997 but was defeated by Brazilian team Atlético Mineiro (1–4, 1–1).

The line-up for that match was: Bossio; Graieb, Ribonetto, Hoyos, Velázquez; Blanco, Pelletieri, Fritzler, Valeri; Acosta, Sand.

Lanús qualified to play the 2012 Copa Libertadores, where the squad got its biggest win in international competitions in history (6–0 against Paraguayan Olimpia in La Fortaleza).

[21][22] The team led by Gabriel Schürrer won its group and reached the round of 16, where it was eliminated by Vasco Da Gama in penalty shootout.

In 2013, Lanús obtained its second international title, the Copa Sudamericana after beating Brazilian club Ponte Preta in the finals.

[23] In May 2016, Lanús won its second league title, the 2016 Primera División after thrashing San Lorenzo by 4–0 in the final match played at River Plate stadium.

In October 2024, the Argentine Association officialised a championship won by Lanús in 1955, the Copa Juan Domingo Perón, organised by the body and the Government of Buenos Aires Province together.

Lanús currently plays in the Liga Nacional de Básquet, the top level of the Argentine league system.