Ronaldo de Assis Moreira (born March 21, 1980 in Porto Alegre, Brazil), better known as "Ronaldinho" (Little Ronaldo), is regarded as one of the world's top football players.

Making a name for himself as the top scorer at the under-17 world championship in Egypt, Ronaldinho began his professional career at Grêmio, and played there from 1998-2001. In his Brazilian national team debut on June 26, 1999, he scored his first international goal, against Paraguay, to win the Copa América. To date, he has won 34 caps for Brazil, scoring 13 goals.

In 2001, Ronaldinho signed a five-year contract with Paris Saint-Germain. The manager of PSG thought that Ronaldinho was too focused on the Paris nightlife rather than on his football. He started playing at the beginning of the 01/02 season due to a protracted legal battle between PSG and Grêmio over the transfer fee. Grêmio finally received $4.5 million.

In 2002, Ronaldinho helped Brazil win the World Cup. One of the highlights of the tournament was a spectacular 35-metre lob he scored against England in the quarter-finals.

In 2003, Ronaldinho made it known he wanted to leave PSG after they failed to qualify for European competition. That set off a bidding war among the elite clubs for his services. On July 19, FC Barcelona snapped him up for 27 million Euro, trumping Manchester United. Ronaldinho justified their purchase, leading them to a second-place finish in the Spanish first division during the 03/04 season.

Together with Samuel Eto'o, Deco, Henrik Larsson and Ludovic Giuly, he comprises part of an awesome strike force which has led Barça to the top of the Spanish league with a large gap down to second place.

On December 20, 2004, Ronaldinho was named FIFA World Player of the Year over Thierry Henry and Andriy Shevchenko.