Club Alianza Lima, more commonly known as simply Alianza Lima, is a Peruvian professional sports club based in La Victoria District of Lima, Peru. The club was founded under the name of Sport Alianza on February 15, 1901 by working-class youth in the Chacaritas neighborhood of Lima. It is widely known for having one of the most historical and successful football teams in Peru; they have won a total of 25 league titles of the Peruvian Primera División and are currently the oldest team playing in that competition, since the club was founded in 1901. According to CONMEBOL, it is considered the most popular club in Peru, and the 6th most popular club in South America, with more than 12 million fans as of April 2016.

Alianza's home stadium is the Estadio Alejandro Villanueva, named after Alejandro Villanueva, one of the most important players in the club's history. The stadium is also popularly known as Matute, the name of the neighbourhood in which it is located. The stadium can hold up to 33,938 spectators.

Alianza Lima is one of the most successful Peruvian football clubs, with a total 59 official titles consisting of 25 Primera División titles, 31 domestic cup titles, 1 supercup, and 1 international cup, the Copa Simón Bolívar. The club has also won numerous regional and short league titles. Alianza enjoyed their most successful period throughout the first decades of their professional era. Their best international performance came in 1976 when they reached the semi-finals of the Copa Libertadores, repeating the feat in 1978. In 1987, tragedy struck Alianza when the entire squad and coaching staff died in an airplane crash as the team returned from an away fixture.

Alianza Lima has had a huge, long-standing rivalry with Universitario de Deportes, the most successful team in Peru with 27 titles, the match is known as the Peruvian Clásico. It is the largest and oldest rivalry in Peru and among the largest in South America; matches very intense and sometimes involve violent fan attacks against each other. Other traditional rivals include Sporting Cristal, Deportivo Municipal, and Sport Boys.

The club has a women's volleyball team that participates in the Liga Nacional Superior de Voleibol. It also has a women's football team that participates in the Liga Femenina along with a basketball, futsal down and Esports team.