Speedster Rio Dyer made his debut for the Dragons in January 2018 against Saracens in the Anglo-Welsh Cup and his league debut less than a month later against Benetton Rugby. A product of the Dragons Academy, Dyer has represented Wales Under-20s and featured in the same squad as the likes of Dewi Lake, Jac Morgan, Tommy Reffell and Sam Costelow in the 2019 U20 World Championship, who were also named in the Wales squad to take on New Zealand, Argentina, Georgia and Australia.

Dyer had a breakthrough campaign during the 2021/2022 season making fifteen appearances for Dragons scoring three tries. The Newport born flyer built on that and his most productive season to date in the 2022/2023 season making fifteen appearances and scoring seven tries making him the club's top try scorer that season which earnt him a Wales Call up and was named Dragons Players' Player of the Season. As of June 2023 Dyer has 14 tries in 45 appearances for his home region.

The Dragons speedster was one of five uncapped players named in Wayne Pivac’s Wales squad for the 2022 autumn campaign. He scored on debut for Wales against New Zealand in the opening game of the 2022 Autumn Nations Series in Cardiff and followed that up with another score against Australia at the Principality Stadium.

Dyer continued his fine form for Dragons which earned him another call up for the 2023 Six Nations Championship, starring for his country as he scored tries in the victory over Italy in Rome and the final score against France in Paris. As of June 2023 Dyer has four tries in just seven caps for Wales and was named in Warren Gatland's Preliminary World Cup squad ahead of the 2023 competition.