Clube de Regatas do Flamengo (English: Flamengo Rowing Club), commonly referred to as Flamengo (Brazilian Portuguese: [flɐˈmẽɡu]), is a Brazilian sports club based in Rio de Janeiro. Their most significant sporting outlet is the football team, which plays in the Campeonato Brasileiro Série A, being one of only five clubs to have never been relegated, along with Chapecoense, Santos, São Paulo and Cruzeiro.

The club was established in 1895, although it did not play its first official football match until 1912. Flamengo is one of the most successful clubs in Brazilian football, having won five Campeonato Brasileiro Série A titles (and the controversial Copa União of 1987), three Copa do Brasil titles, one Copa Intercontinental, one Copa Libertadores and holds a record of 34 Campeonato Carioca trophies. Due to its low capacity, Flamengo's home stadium, Gávea, hasn't been used in official matches since 1997 and the club usually opts for the Maracanã, the biggest football stadium in Brazil, with a capacity of 78,838. Since 2016, the club have been playing most home games at the Ilha do Urubu, a temporary home until a favorable deal is made with the Maracanã stadium's administration.

Its traditional playing colors are red and black striped shirts with white shorts and red and black striped socks. Ironically these colors were the ones utilized by the German National Team Mannschaft in Brazil's epic 7-1 loss in the 2014 World Cup, known as the Mineirazo. The team, with Zico as its protagonist, achieved the most prestigious accolade in South American football when they defeated Cobreloa 2–0 in the Estadio Centenario in Montevideo to become champions of South America. They subsequently became known as the Geração de Ouro, or the Golden Generation. That same year, Flamengo became world champions after defeating Liverpool 3–0 in Tokyo.

Flamengo is the most popular team in Brazil, with over 39.1 million supporters as of 2010, and was voted by FIFA as one of the most successful football clubs of the 20th century. It is also one of Brazil's richest football clubs in terms of revenue, with an annual revenue of R$347.0 million ($130.06 million/€107.5 million) in 2014, and the second most valuable club in South America, worth over R$855.4 million ($424.4 million/€327.9 million) in 2013. The club has long-standing rivalries with nearby neighbors Fluminense, Botafogo and Vasco da Gama. There is also an interstate rivalry with Atlético Mineiro and a fierce one with Corinthians.