Christine Ijeoma Ohuruogu // ⓘ, MBE (born 17 May 1984) is a British former track and field athlete who specialised in the 400 metres, the event for which she is an Olympic, World and Commonwealth champion.

Known for her strength endurance, consistent pacing, her gift for maintaining speed in the final straight as rivals struggled and slowed, and her capacity to peak for major championships, Ohuruogu retired in 2017, a year after winning her final senior global medal, a bronze as part of the Great Britain Olympic 4 × 400 metre relay team, her 12th overall global medal.

Upon retirement, Ohuruogu made public her plan to begin her second career, seeking to qualify in law, with the aim of being called to the Bar.

After reaching the semi-final at the 400 m at the 2005 World Championships in Athletics she won a bronze medal in the women's 4 × 400 m relay together with Lee McConnell, Donna Fraser and Nicola Sanders.

Ohuruogu won a gold medal for England in the 400 m at the 2006 Commonwealth Games in a personal best time of 50.28 seconds, beating favourite Tonique Williams-Darling in both the semi-final and the final.

[19] Within 24 days of the end of her year-long competition suspension she returned to win the gold medal at the 2007 World Championships in Osaka.

She ran the final leg in the 4 × 400 m relay for England, where the team finished over a second ahead of Australia, with Ohuruogu pulling away at the end.

[19] Under IAAF and British Olympic Association rules, she received a one-year ban for missing these tests, which expired on 5 August 2007.

[23] The final test missed occurred when Ohuruogu failed to inform the testers of a last-minute change of training venue after a double-booking.

Due to the circumstances, the Independent Committee stated "There is no suggestion, nor any grounds for suspicion, that the offence may have been deliberate in order to prevent testing", and that a fair ban would have been 3 months.

[24] Ohuruogu suggested that she would probably leave Britain and compete in the Olympics for another country if her appeal was unsuccessful, but confessed "I haven't really given it any serious thought.".

[23] She had only run five competitive races before the final since her suspension; however, she won the individual 400m, taking the only gold medal for Great Britain at the Championships.

[32] In preparation for the European Indoor Championships in Turin, Ohuruogu set personal bests in the 60 metres and 200 m at the Birmingham Grand Prix.

[35] While she won the 400 m national title at the UKA Championships in Birmingham that July, her times and finishes over the distance at IAAF Golden League meets were unimpressive.

[37] A hamstring problem caused her to withdraw from the London Grand Prix, raising doubts that she would be able to defend her World title.

In the Indoor World Championships 4 × 400 m relay in Istanbul Ohuruogu, after legs from Shana Cox and Nicola Sanders took over in third place for Great Britain.

Ohuruogu handed over to Perri Shakes-Drayton to hold off Sanya Richards-Ross to win Great Britain's first ever IAAF World Indoor Championships medal in the Women's 4 × 400 m relay.

Despite an injury-ravaged season, Ohuruogu reached the final of the 400m at the World Championships in Beijing, the scene of her Olympic triumph in 2008, as the defending champion.