Prime Suspect is a British police procedural television drama series. It stars Helen Mirren as Jane Tennison, one of the first female Detective Chief Inspectors in Greater London's Metropolitan Police Service, as she rises to rank of Detective Superintendent whilst confronting the institutionalised sexism that exists within her job.

A prime suspect or key suspect is a person who is considered by the law enforcement agency investigating a crime to be the most likely suspect. The idiom "prime suspect" believed to have originated in 1931. "Key suspect" is seen as early as 1948.