He went on the break his personal best times for the 50 m and 100 m freestyle events, earning himself a silver and bronze, as well as a spot on the British team for the 2013 World Championships being held in Barcelona. Unsurprisingly, Proud did incredibly, finishing 18th in the 50 m freestyle, and 11th in the 50 m butterfly. In 2014, still only 19 years old, Proud won his first senior international medals on his Commonwealth debut for England at Glasgow. The following month, Proud won a gold in the 4 × 100 m medley relay and a bronze in the 50 m butterfly for Team GB at his first European Championships.