Evans won Olympic silver for Great Britain in the welterweight division, losing in the final to Kazakh boxer Serik Sapiyev.

[8] He also entered the 2008 AIBA Youth World Boxing Championships in Guadalajara but was defeated by eventual winner, Irish fighter Ray Moylette.

[9] In the same year, Evans was picked to travel with the British side to the 2008 Summer Olympics in Beijing at the age of 17 in order to experience the atmosphere at the games before being selected for the GB development squad.

[3] Evans was also one of eight fighters from St Josephs who were chosen to represent Wales in the Senior Novice Welsh Championships against a team from the United States in 2009.

Evans met American fighter Errol Spence Jr. where, despite a strong start to the fight, he eventually suffered a 15–9 points defeat.

[11] The same year Evans competed in the 2010 Commonwealth Games in Delhi but suffered a first round points defeat to Mauritanian fighter Kennedy St-Pierre.

[4] In preparation for the games, Evans relocated to the Team GB gym run by Robert McCracken and also sparred with Carl Froch ahead of his IBF super-middleweight title fight with Lucian Bute.

[18] Evans made his Olympic debut on 29 July 2012 against Algerian Ilyas Abbadi in front of a partisan home crowd at the ExCeL London.

Boxing pundit Steve Bunce commented the Evans "picked his punches with ease" as he won the fight by a comfortable 18–10 points decision.

Evans fought back to tie the fight at 5–5 at the end of the second round before producing a "masterclass" in the third to secure an 11–7 victory and advance to the quarter-finals.

[20] The Canadian team unsuccessfully appealed the decision, claiming Evans should have been deducted points for receiving persistent warnings from the referee.

He entered the tournament as the number one ranked welterweight but suffered a defeat to German Arajik Marutjan in the early rounds of the competition.