2007 | European Union Amateur Championships In 2007, Barnes competed at the
EU Championships in Dublin. He had his medal hopes crushed however when he suffered an eye injury. With bleeding found behind his retina, Barnes was forced out of the competition.
2007 | World Amateur Championships At the
World Championships in Chicago Barnes missed out on a bronze medal after he was defeated by China's
Zou Shiming in the quarter-finals, Zou went on to win the
gold medal. However, Barnes qualified for the
2008 Olympics by virtue of getting to the quarter-finals. • 1st round – defeated Choi Jon Chuk
North Korea 33–19 • Round of 32 – defeated Sadegh Zade Faraj
Iran 30–10 (RSCO) • Round of 16 – defeated Kenji Ohkubo Japan 24–6 • Quarter final – lost to
Zou Shiming China 8–22
2008 | European Union Amateur Championships In 2008, Barnes returned to
EU Championships, this time in
Cetniewo, Poland. Barnes made it to the final where he lost to Hungarian fighter
Pál Bedák. The silver medal was enough to secure his place at the Summer Olympics.
2008 | Olympic Games Barnes won Ireland's inaugural medal, at the 2008 Summer Olympics, by winning his quarter final bout in the
light flyweight division. Barnes won a bronze medal after he was defeated in a second match with Shiming Zou in the semi-final, in a match where replays showed some of Barnes landed punches counted as points for Zou. • Round of 32 – bye • Round of 16 – defeated
José Luis Meza 14–8 • Quarter final – defeated
Łukasz Maszczyk 11–5 • Semi-final – lost to
Zou Shiming 0–15
2010 | European Amateur Championships On 12 June 2010, Barnes won the gold medal in the light flyweight division at the
2010 European Amateur Boxing Championships. Barnes, a 4–1 winner over Azerbaijan's Elvin Mamishzade, was 1–0 up at the end of the first round, 3–1 ahead at the end of the second and sealed the victory with a final point in the third for 4–1.
2010 | Commonwealth Games Barnes represented Northern Ireland at the
2010 Commonwealth Games. He won the gold medal, defeating Namibia's Jafet Uutoni 8–4 in the final. • Round of 16 – defeated Iain Butcher 4–2 • Quarter final – defeated Andrew Moloney 5–3 • Semi final – defeated Amandeep Singh 5–0 • Final – defeated Jafet Uutoni 8–4
2012 | Olympic Games At the
2012 Summer Olympics he defeated
Thomas Essomba from Cameroon 15–10 then beat India's
Devendro Singh in his quarter-final bout to guarantee himself at least another bronze medal. In doing so, he became the inaugural Irish boxer to win medals at two consecutive Summer Olympics. For the semi-final, Barnes once again drew Chinese superstar
Zou Shiming, who had defeated Barnes in the
2008 semi-finals before taking gold. Barnes gave a fearless performance against the three time World champion, with the judges tying them 15–15 on the scorecards, only for Barnes to lose via a 45–44 countback. Shiming once again went on to win gold. • Round of 16 – defeated
Thomas Essomba 15–10 • Quarter final – defeated
Devendro Singh 23–18 • Semi-final – lost to
Zou Shiming 15–15 / 44–45 (CB)
2014 | Commonwealth Games As captain of the Northern Ireland boxing team in 2014 at
Glasgow, Barnes led the way by winning gold in the flyweight division defeating India's
Devendro Singh. It was the first time a Northern Irish boxer had successfully defended a Commonwealth title.
2015 | World Series of Boxing Barnes competed in the
WSB for the 2014–2015 season. Along with
Michael Conlan, he was drafted by Italia Thunder. His first fight came against Magomed Ibiyev of the Baku Fires, in
Baku. Barnes won with a 49–46, 49–46, 50–44 unanimous decision. His second fight was another win, this time over Anthony Ortiz as Italia Thunder met the Puerto Rico Hurricanes. The judges scored it 48–47, 49–46, 49–46 as Barnes took another unanimous decision win. The Hussars of Poland were next up, in
Konin. Barnes continued his perfect start to the season with a landslide 50–45, 50–43, 50–45 victory over Sebastien Jagodzinski. His record for the season went to four wins with four unanimous decisions, when he defeated Kazakh fighter Temirtas Zhussupoy of the Astana Arlans in
Kazakhstan. His next fight was in
Maiquetia, with a split decision win over Caciques de Venezuela's Finol Rivas. The judges scored the bout 49–45, 49–45, 47–48 in favour of Barnes.
2016 | Olympic Games Barnes was also chosen to be the bearer of the
Flag of Ireland Tricolour at the 2016 Summer Olympics, something that Barnes considered an "incredible honour". At the
2016 Summer Olympics Barnes was defeated 2–1 by
Samuel Carmona in the round of 16.
Provincial and National Titles Barnes lost the
Ulster title in 2005, 2006 and 2007. He faced Jimmy Moore from
Limerick in each of his national finals being runner up in 2006 but winning the
All-Ireland title in 2007 and 2008. ==World Series of Boxing record==