Peter Charles John, Baron John of Southwark is a British politician.
John became leader of Southwark Labour in 2004, after being first elected to South Camberwell ward in 2002. In 2020, he stepped down as leader of Southwark London Borough Council after 10 years. He was given a life peerage as a part of 2025 Political Peerages and he was created Baron John of Southwark, of Pattiswick in the County of Essex, on 7 January 2026.