The Taça Guanabara (English: Guanabara Cup) is an annual football tournament attached to the Campeonato Carioca, the state football league in the Rio de Janeiro state. It has been organized since 1965 by the Rio de Janeiro State Football Federation. It has had different formats throughout its history.

In its first seven editions (1965, 1966, 1967, 1968, 1969, 1970 and 1971), the Taça Guanabara was a tournament in its own right, unrelated to the Campeonato Carioca, and the winner would represent Rio de Janeiro in the Taça Brasil national league competition. From 1972 onward, the cup became the first round of the Campeonato Carioca. Since 2021, the Taça Guanarabara is the first single round-robin phase of the Campeonato Carioca.

The most successful team in the tournament's history is Flamengo, who have won 24 times.

The Taça Guanabara and the Taça Rio has become, throughout its history, recognized for the various changes in its format, causing confusion for many spectators.^[1][2]

Since 2021, the Taça Guanarabara is the first single round-robin phase of the Campeonato Carioca, played by 12 teams. The team that finishes with the most points is the champion. The four best teams advance to the final stage of the Campeonato Carioca, and the clubs that finished 5th to 8th places compete in the Taça Rio.^[3]

The first season of the tournament was held in 1965. At the time, the tournament was considered a separate competition unrelated to the Campeonato Carioca. In its first years, its purpose was to define the Guanabara representative in the Taça Brasil, but it kept being played even after the Taça Brasil's last edition. In 1971, the tournament became the first stage of Campeonato Carioca but is still considered a separate competition to a certain extent, with a trophy awarded to the winner of the tournament.

The current format has been used throughout the tournament's history with the exception of the 1994 and 1995 editions.

In 1994, twelve teams were divided into two groups (similar to the current format). However, in the group stage, teams not only played against teams from their same group, but also played against the teams from the other group in the second phase of the group stage (similar to the Taça Rio format). After the group stage, the first placed team in each group faced each other in the Taça Guanabara final. Semi-finals were not played. The Taça Guanabara final results had no bearing on the Campeonato Carioca. The two highest placed teams of each Taça Guanabara group entered the final phase of Campeonato Carioca. Those four teams played a double round-robin tournament to contest the Campeonato Carioca championship.^[4]

In 1995, the number of teams increased to 16 while the format remained similar to 1994: two groups of 8 teams contested two group stage phases. After the group stage, the top team of each group competed in the Taça Guanabara final, with the winner being awarded one point in the final phase of Campeonato Carioca. The first placed team in each group after the first and second phase of the group stage also received one extra point for a total of five "bonus" points contributed towards teams in the Campeonato Carioca. The top four teams in each group then contested the final phase of Campeonato Carioca in a double round-robin tournament to determine the winner of Campeonato Carioca.^[5] Because of these format changes, Taça Rio was not held in these three years. Since 1996, the old format has been adopted again.

• Flamengo 24 titles
• Vasco da Gama 13 titles
• Fluminense 12 titles
• Botafogo 8 titles
• América 1 title
• Americano 1 title
• Volta Redonda 1 title

Since 1990, the winner of the Taça Guanabara has also won the State championship in 1992, 1994, 1997, 1998, 1999, 2001, 2003, 2004, 2006, 2007, 2008, 2010, 2011, 2012, 2013, 2014, 2016, 2020, 2021, 2022, and 2023.

• Campeonato Carioca
• Taça Rio