Club Atlético Peñarol (Spanish pronunciation: [kluβ aˈtletiko peɲaˈɾol] ), more commonly referred to as Peñarol, is a Uruguayan professional football club based in Montevideo. The club currently competes in the Uruguayan Primera División, the highest tier in Uruguayan football.

The name of the club comes from the neighborhood on the outskirts of Montevideo, which itself takes its name from Pinerolo, a town in the metropolitan area of Turin, in the Italian region of Piedmont. The club's origin dates back to the 28th of September 1891, when the club was initially established as the Central Uruguay Railway Cricket Club (also known by its acronym CURCC), founded by mostly British railway workers for the practise of cricket. The club was renamed as Peñarol on 13 December 1913; the continuity between the football section of the CURCC and Peñarol has sparked significant controversy in Uruguayan football, as some football pundits have argued that while Peñarol inherited its tradition from the CURCC and there is a sociological continuity between the two, legally they are two separate institutions, as the CURCC would have continued to exist until its dissolution on 22 January 1915, though merely was by then a recreational branch for the employees of the railway company. However, the Uruguayan Football Association has recognized Peñarol as the continuity of CURCC since 1914.

By the 1910s, Peñarol began to establish themselves as a promising club in national and international football. The introduction of the FIFA World Cup in 1930 helped elevate the presence of Uruguayan football, including Peñarol; several members of the team were products of the club. The start of the 1940s ushered in a golden generation for Peñarol, as the following four decades the club would have won several international tournaments led by generational talents including Diego Aguirre, Néstor Gonçalves, Fernando Morena, Juan Alberto Schiaffino, and Alberto Spencer. By the 1990s, Peñarol experienced a decline in form, with fewer domestic and international titles compared to the previous decades. However, the club has seen a resurgence in international competition since the 2010s.

Although the original colors of the CURCC were black and orange, Peñarol has consistently identified with yellow and black throughout its history, inspired by the Stephenson's Rocket and the railway workers' union. The club throughout its history has also participated in other sports, such as athletics, basketball, cycling, futsal, rugby union, and women's football. Its main focus, however, has always been on men's football, a sport in which the club excels. The club currently host their matches at the 40,000-capacity Estadio Campeón del Siglo since 2016, having previously played at Estadio Centenario since 1933. Peñarol currently have 80,000 associates.

Peñarol is considered one of the most prestigious football clubs in the sport. In September 2009, the club was recognized as the best South American club of the 20th century by the IFFHS. In international competition, Peñarol is the third-highest Copa Libertadores winner, having won it on five editions (1960, 1961, 1966, 1982, and 1987), and shares the record for Intercontinental Cup victories with three (1961, 1966, and 1982). In domestic football, Peñarol has won 42 tournaments in its era, and considering the titles won by their predecessor, it has claimed 51 championships overall. The club has never been relegated and has many long-standing rivalries, most notably El Clásico Uruguayo with Club Nacional de Football. The derby is considered one of the oldest in international football, with their first meeting on 15 July 1900 with a 2–0 victory. Since then, they have faced each other in more than 500 occasions. As of 2024, Peñarol currently holds the advantage in the head-to-head record.