Impulsora del Deportivo Necaxa S.A. de C.V. (pronounced [ne.ˈkaɣ.sa]); also known as Club Necaxa, is a Mexican professional football club based in the city of Aguascalientes. It competes in Liga MX, the top division of Mexican football. It was founded on August 21, 1923 in Mexico City by the Scottish-born engineer William H. Fraser. In 2003, it changed its headquarters to the city of Aguascalientes, in the state of the same name. The team plays its home games at the Estadio Victoria.

The club has won 3 Liga MX titles, four Copa MX titles, two Campeón de Campeones and one Supercopa MX. Internationally, It won one CONCACAF Champions Cup and one CONCACAF Cup Winners Cup. It was the first team to win the double in Mexico, winning the league title and the cup tournament in the same season, this in the amateur era (1932–33 season), thus taking the nickname Campeonísimo, becoming the first team in Mexican football to carry that nickname.

At the international level and beyond its confederation titles, the club's most notable performance was obtaining third place in the 2000 FIFA Club World Championship held in Brazil.

It occupies 7th place in the list of the International Federation of Football History and Statistics of the Club of the Century of North and Central America (1901-2000), being the best-placed Mexican club.

Necaxa was founded on August 21, 1923 by Scotsman William H. Fraser, an engineer and owner of the Light and Power Company (Compañía de Luz y Fuerza) in the state of Puebla. As a student in Scotland Fraser played football and was a strong advocate for the sport. Fraser consolidated the teams of the Light and Power Company and the Street Car operators Compañia de Luz y Fuerza and Tranvías into one.

Fraser supported the newly merged team with company revenue and funds. In addition, the Light and Power Company offered steady employment to players in an era where half of the players were playing at an amateur level. However, the Mexican football federation did not allow teams to be named after private companies, so the team changed its name to Necaxa, after the Necaxa River that was close to the electrical plant.

Historians assert that the colors and Necaxa's crest came from following the arrival of the Cornish community in Mexico, the Cornish community flourished and stayed in Central Mexico until the Mexican Revolution in 1910. Although the Cornish community in Mexico broadly returned to Cornwall, they left a cultural legacy; Cornish pasties, Cornish mining museums, a Cornish Mexican Cultural Society and football, are part of the local heritage and tradition in and around Mineral del Monte. In 1923, it was decided Necaxa team would field players regardless of race and nationality.

In that era, the team was called "Los Electricistas" (The Electricians). The team adopted the colors red and white as their team colors, earning them the nickname "Los roji-blancos". During this period, the oldest rivalry in Mexican football began to form, between Necaxa and Atlante F.C.