Ronaldo de Assis Moreira (born 21 March 1980), commonly known as Ronaldinho or Ronaldinho Gaúcho,is a Brazilian footballer. His main playing position is as an attacking midfielder or forward. He won the FIFA World Player of the Year award in 2004 and 2005. Renowned for his technique, tricks, dribbling, overhead kicks, no-look passes and free kicks, Ronaldinho is widely regarded to be one of the best footballers of his generation.

"Ronaldinho", the diminutive and term of endearment for "Ronaldo", is accompanied in Brazilian usage by the nickname "Gaúcho" (since he hails from southern Brazil), in order to distinguish him from fellow footballer and countryman Ronaldo, who was known as "Ronaldinho" in Brazil beforehand. Ronaldo simply went by his first name upon his move to Europe, thereby allowing Ronaldinho to drop the "Gaúcho" and go by the name Ronaldinho abroad.

Ronaldinho has played 97 matches and scored 33 goals for the Brazil national football team. He was an integral part of the 2002 FIFA World Cup winning team, starring alongside Ronaldo and Rivaldo in an attacking trio, and was named in the FIFA World Cup All-Star Team.

At club level, prior to his move to Atlético Mineiro, Ronaldinho played for Grêmio, Paris Saint-Germain, FC Barcelona, Milan and Flamengo. With Barcelona, he won the UEFA Champions League in 2006 and the Ballon dOr in 2005. He became a Spanish citizen in January 2007. Ronaldinho was named in the FIFA 100, a list of the worlds greatest living players compiled by Pelé, and to the FIFPro World XI from 2005–2007.                      

Ronaldinho was born in the city of Porto Alegre, the state capital of Rio Grande do Sul. His mother, Dona Miguelina Elói Assis dos Santos (daughter of Enviro Assis),is a former salesperson who studied to become a nurse. His father, João de Assis Moreira, was a shipyard worker and footballer for local club Esporte Clube Cruzeiro (not to be confused with Cruzeiro).He suffered a fatal heart attack in the family swimming pool when Ronaldinho was eight. After Ronaldinhos older brother, Roberto, signed with Grêmio, the family moved to a home in the more affluent Guarujá section of Porto Alegre, which was a gift from Grêmio to convince Roberto to stay at the club. Robertos career was ultimately cut short by injury. Today, Roberto acts as Ronaldinhos manager, while his sister Deisi works as his press coordinator.

Ronaldinhos football skills began to blossom at the of age 8, and he was first given the nickname Ronaldinho because he was often the youngest and the smallest player in youth club matches. He developed an interest in futsal and beach football, which later expanded to organized football. His first brush with the media came at the age of thirteen, when he scored all 23 goals in a 23–0 victory against a local team. Ronaldinho was identified as a rising star at the 1997 U-17 World Championship in Egypt, in which he scored two goals on penalty kicks.

Ronaldinho became a father for the first time on 25 February 2005, after Brazilian dancer Janaína Mendes gave birth to their son, who was named João after Ronaldinhos late father.

Ronaldinho is one of few Brazilian players to have played at every international age level. He was part of the first Brazilian team to win the FIFA U-17 World Championship in 1997, in which his first goal was a penalty against Austria in the first group match, which Brazil won 7–0. Ronaldinho finished with two goals and was awarded the Bronze Ball award as Brazil scored a total of twenty-one goals while only conceding two.

1999 was a busy year for Ronaldinho in terms of international play. First he appeared in the South American Youth Championship, where he scored three goals and helped the U20s to reach the third place. Then he took part in that years FIFA World Youth Championship, scoring his first goal in Brazils last group match. In the round of sixteen, he scored two first-half goals in a 4–0 win over Croatia, and finished with three goals as Brazil were eliminated by Uruguay in the quarterfinals.

Ronaldinho participated in his first World Cup in 2002, as part of a formidable offensive unit with Ronaldo and Rivaldo, dubbed the "three Rs", who were also on the 1999 Copa América winning squad.Ronaldinho appeared in five matches during the tournament and scored two goals, as well as contributing several important assists. His first goal came in the group stage match against China, which Brazil won 4–0.

The most memorable match in Ronaldinhos World Cup career took place in the quarterfinal against England on 21 June. With Brazil trailing after Michael Owens 23-minute strike, Ronaldinho turned the game around. Having received the ball inside his own half, Ronaldinho ran at the England defence and went past star defender Ashley Cole with a trademark step over before passing the ball to Rivaldo on the edge of the penalty area to score the equalising goal just before half-time.Then, in the 50th minute, Ronaldinho took a free-kick from 40 yards out which curled into the top left corner of the net, completely surprising Englands goalkeeper David Seaman, giving Brazil a 2–1 lead. However, seven minutes later, he was controversially sent-off for a foul on Englands defender Danny Mills. Ronaldinho was suspended for the semifinal, but returned to Brazils starting lineup for the 2–0 victory over Germany in the final as Brazil won the World Cup for the fifth time.