With fourteen medals and six titles in Olympic and World Championships, Whitlock is the most successful gymnast in British history.

[8] He returned three months later and joined South Essex Gymnastics Club in Basildon, where he is coached by his brother-in-law Scott Hann.

[10] Whitlock won gold on pommel horse and floor exercise and silver in the all-around at the 2010 Junior European Championships held in Birmingham.

[21] Whitlock represented Great Britain at the 2012 Summer Olympics in London alongside Smith, Sam Oldham, Daniel Purvis, and Kristian Thomas.

[22][23] He also won the bronze medal in the pommel horse event final behind Hungary's Krisztián Berki and teammate Smith.

[24] Whitlock began the season at the Internationaux de France where he won the silver medal on the pommel horse behind Olympic champion Krisztián Berki.

[26] At the Anadia World Challenge Cup, he was upset in the pommel horse final by Colombia's Jhonny Perez.

[29] At the European Championships in Sofia, Whitlock and his Great Britain teammates won the team silver medal behind Russia.

[30] In event finals, he won the gold medal in pommel horse ahead of the defending Olympic champion Krisztián Berki.

He did not qualify for any of the individual finals, including the all-around due to the two-per-country rule as he finished behind teammates Daniel Purvis and Nile Wilson.

[38] He won the silver medal with a score of 90.473, just under a point and a half behind defending Olympic all-around champion Kohei Uchimura.

[39] Due to illness, Whitlock only competed on pommel horse at the British Championships, where he won the silver medal behind Louis Smith.

Then in the pommel horse final, he became the first British man ever to win a World Championship gold medal, by 0.100 over teammate Smith.

[51] On 12 July 2016, Whitlock was selected to represent Great Britain at the 2016 Summer Olympics, along with Louis Smith, Nile Wilson, Kristian Thomas and Brinn Bevan.

[58] In March, Whitlock announced that he would take six months off from competition, missing the London World Cup and the European Championships.

[68] He failed to win a third consecutive pommel gold at the World Championship, despite receiving the same score of 15.166 as the winner Xiao Ruoteng.

[75] At the 2020 Summer Olympics in Tokyo, Japan, Whitlock competed for Great Britain alongside Joe Fraser, James Hall, and Giarnni Regini-Moran.

[76] Whitlock opted not to defend the floor exercise title, concentrating instead on the pommel horse, which he went on to win with a score of 15.583.

[79] He was selected for the 2023 World Championships team alongside Jake Jarman, James Hall, Harry Hepworth and Courtney Tulloch.

[84][85] In June he was officially selected to represent Great Britain at the 2024 Summer Olympics alongside Joe Fraser, Jake Jarman, Harry Hepworth, and Luke Whitehouse.

[87] Whitlock qualified for the pommel horse final where he was attempting to become the first male gymnast to medal at four successive games on a single apparatus[88] but he finished fourth.