Riots often occur in reaction to a perceived grievance or out of dissent. Riots may be the outcome of a sporting event, although many riots have occurred due to poor working or living conditions, government oppression, conflicts between races or religions.
Rapid urbanization has led to the rise of urban riots, often inner city. John F. McDonald and Daniel P. McMillen have identified Los Angeles's Watts Riots, in 1965, as the first "urban riots" in the United States. The analyses of urban riots in terms of urban conditions influenced the emerging field of urban economics in the 1960s.
Riots have occurred before the rapid urbanization starting in the mid-20th Century, hence the occurrence of riots in urban areas in itself is not special. While a riot may be initially sparked by a specific event, scholars, commentators and commissions have sought to identify the deeper reasons and have identified a number of urban conditions that may underline urban riots. These urban conditions are often associated with urban decay more generally and may include: discrimination, poverty, high unemployment, poor schools, poor healthcare, housing inadequacy and police brutality and bias.
This is a list of riots that have occurred, mostly in the United States and the UK, in the context of urban conditions and more broadly urban decay.