: Public expenditure on large events such as the London 2012 Olympic Games is often justified by the potential legacy of urban regeneration and its associated health and well-being benefits for local communities. In the Olympic Regeneration in East London Study, we examined whether there was an association between urban regeneration related to the 2012 Games and improved mental health in young people. Adolescents aged 11-12 years attending schools in the Olympic host borough of Newham in London or in 3 adjacent comparison London boroughs completed a survey before the 2012 Games and 6 and 18 months after the Games (in 2013 and 2014, respectively). Changes in depressive symptoms and well-being between baseline and each follow-up were examined. A total of 2,254 adolescents from 25 randomly selected schools participated. Adolescents from Newham were more likely to have remained depressed between baseline and the 6- and 18-month follow-up surveys (for 6-month follow-up, relative risk = 1.78, 95% confidence interval: 1.12, 2.83; for 18-month follow-up, relative risk = 1.93, 95% confidence interval: 1.01, 3.70) than adolescents from the comparison boroughs. No differences in well-being were observed. There was little evidence that urban regeneration had any positive influence on adolescent mental health and some suggestion that regeneration may have been associated with maintenance of depressive symptoms. Such programs may have limited short-term impact on the mental health of adolescents.<br/>