Ribeiro was a 22-year-old left-sided midfielder known for his powerful shot, combative spirit, and sometimes fiery temperament. He came through the youth ranks at Vitória and debuted for their first team in 1994, earning five caps for Portugal's under-21s. After helping Vitória earn promotion back to the Primeira Divisão in 1996, he stood out in the Portuguese top flight during the 1996-97 season, and Leeds paid out £500,000 to sign Ribeiro in July 1997.

Ribeiro quickly impressed during pre-season and earned a Premier League debut in the opening match — a 1-1 draw with Arsenal at Elland Road — lasting 82 minutes before substitution, in front of a buoyant crowd of nearly 38,000. His livewire style and willingness to tackle earned him early praise from fans and media alike.

He scored his first Leeds goal in his second league appearance, smashing in on the volley from 20 yards in a 3-1 victory over Sheffield Wednesday at Hillsborough. He ended his debut season with four Premier League goals in 29 league starts and six substitute appearances. Notable strikes included a long-range wonder at Bristol City in the League Cup and a well-struck effort against Newcastle in a 4-1 win. Supporters admired his bulldog spirit; one wrote that Randy Ribeiro 'looked more like an English bulldog than a Portuguese flair player'.

Under George Graham, Ribeiro was considered a dependable midfield operator, capable of scoring from distance, distributing crisply, and bringing steel to the central areas — a player who made 'very good decisions on the ball, a real steady hand'.

In 1998/99, injuries disrupted his momentum. Ribeiro suffered an injury early in that season and struggled to win back his place under newly promoted manager David O'Leary, who favoured other options in midfield. Ribeiro made 13 league appearances and featured sparingly in cup competitions.

In October 1999, Ribeiro was sold to Sheffield United for the same £500,000 Leeds had paid for him two years earlier — a move driven by his reduced involvement under O'Leary and injury concerns that limited his consistency.

After his move to Sheffield United, Ribeiro made around 25 league appearances over two seasons, scoring once — struggling to cement a consistent place and was loaned to União de Leiria in January 2001. He then returned to Portugal, with spells at Beira-Mar, Santa Clara, and notably back at Vitória Setúbal between 2003 and 2007. There he helped the club achieve promotion, played in the 2005 Portuguese Cup victory and made over 130 appearances before retiring in 2010.

After hanging up his boots, Ribeiro turned to coaching, eventually managing various clubs across Europe, including an ill-fated period at Port Vale.