Rivaldo switched to FC Barcelona in 1997 in a transfer deal securing Deportivo a 4 billion pesetas (around $26 million) transfer fee, with Sir Bobby Robson convincing Barcelona to sign Rivaldo ahead of Steve McManaman by saying that Rivaldo would guarantee the team many goals.

Rivaldooo...that's magnificent. Ohh wonderful. You just could not envisage such a finish to the season. The Brazilian completes a hat-trick, a minute from time with the most delightful of goals you will ever see. A goal in a million, to earn many many millions next season. — Sky Sports commentary on Rivaldo's last minute overhead bicycle kick match winner against Valencia in La Liga on 17 June 2001 to qualify Barcelona for next season's UEFA Champions League.

In his first season at Barcelona, Rivaldo was the second top goalscorer with 19 goals in 34 matches, as Barcelona won The Double of La Liga and Copa del Rey. In 1999, he won another La Liga title with Barcelona, and once again was the league's second highest scorer with 24 goals. In 1999, Rivaldo was named FIFA World Player of the Year and he also received the Ballon d'Or. After Barcelona's unsuccessful Champions League campaign, Rivaldo was linked with a move away from Camp Nou. Then Manchester United captain Roy Keane was reported stating Rivaldo was the player he most wanted United to sign.

At times around the turn of the century he was impossible to play against, and never more so than here. The quality of the goals was outstanding, but the context made his performance legendary. After just 18 months and 17 days, the book on the greatest hat-trick of the 21st century was already closed. — Rob Smyth of The Guardian on Rivaldo's hat-trick against Valencia in June 2001.

In his third season at Barcelona, Rivaldo fell out with manager Louis van Gaal, when he insisted playing as a playmaker rather than on the left wing. Even though he had a strained relationship with Van Gaal, Rivaldo went on to score 10 goals in the season's Champions League as the club reached the semi-finals. Van Gaal was fired in June 2000.

In the following 2000–01 season, Rivaldo was once again the second highest goalscorer of the league, with 23 goals. In the last game of the season, against Valencia CF, Rivaldo scored a hat-trick to win the game 3–2. Frequently ranked the greatest hat-trick ever, his first goal was a trademark bending free kick that curled into the bottom right corner, the second saw him send the Valencia player the wrong way with a feint before a strike with little back-lift from 25 yards swerved into the bottom left corner of the net, and his match-winning third occurred after Rivaldo controlled the ball with the chest from the edge of the 18 yard box and executed an overhead bicycle kick in the 89th minute, which he regards as the best goal of his career. An ecstatic Rivaldo ripped off his jersey and started swinging it over his head during his goal celebrations, while Barcelona club president Joan Gaspart broke with convention in the stadium's VIP box by punching the air with both fists and yelling his delight next to the opposition delegation. The win pushed Barcelona ahead of Valencia to secure a place in the 2001–02 Champions League. After the game Rivaldo stated; "What happened tonight has been incredible. I dedicate the winning goal to all the players who have fought so hard all season and all the supporters who have suffered so much. I'm delighted to have made them happy with my goals." He scored a total of 36 goals that season.