A total of twenty clubs compete in the league's regular season. División Mayor del Fútbol Profesional Colombiano, better known as Dimayor, operates the league system of promotion and relegation for both Categoría Primera A and Categoría Primera B leagues. Since its founding in 1948, fourteen teams have been crowned as the Colombian football champions. The most successful club is Atlético Nacional with 15 titles.
Before 1948 there was no professional football league in Colombia. The first clubs were formed in Barranquilla and Bogotá: Barranquilla FC, Polo Club, Escuela Militar and Bartolinos, although the game took a while to develop in popularity. The 1918 Campeonato Nacional was the first tournament played between Colombian clubs, followed by the Copa Centenario Batalla de Boyacá. Independiente Medellín, founded on 15 April 1913, is the oldest club that remains as a professional club. The first tournament was organised by Colombian Football Federation and DIMAYOR in 1948. In the tournament 10 teams signed up (each had to pay a fee of 1,000 pesos): one of Barranquilla, two of Bogotá, two of Cali, two of Manizales, two of Medellín and two of Pereira. 252 players were registered as follows: 182 Colombians, 13 Argentines, 8 Peruvians, 5 Uruguayans, 2 Chileans, 2 Ecuadorians, 1 Dominican and 1 Spanish.
From 1949 to 1954 the DIMAYOR, the organiser of the league, broke away from FIFA after a dispute with Adefútbol, the existing amateur football authority in Colombia, in a period known as El Dorado. Therefore, all Colombian teams were suspended from playing international football. The Colombian national team was also under sanction. However, FIFA sanction did not hurt the league; instead, the Colombian league reached its golden era during the period. During the early 1950s the league was dominated by Millonarios FC as they won consecutive championship with recognised players such as Alfredo di Stéfano.
In 1968 the league followed the pattern common in South America by splitting into two separate competitions per season, the Apertura (February to June) and the Finalización (July to December). During the 1980s saw the emergence of América de Cali as they won 5 consecutive championships and so far are the only ones who have done it. In 1991 a second division was added to the first with a third, now defunct. The Copa Colombia appeared in 1950 although this knockout competition was only contested from time to time until 2008 when it became an annual tournament.Since 2002 the Apertura and Finalización tournaments became separate with each having their own champion, which meant two champions per year. Since that change Atlético Nacional of Medellín have dominated the league, in the 2007 season they would become the first and only club to win both the Apertura and Finalización tournaments, they would repeat this in the 2013 season as well.