Mansion House is a London Underground station in the City of London which takes its name from Mansion House, the residence of the Lord Mayor of London. It opened in 1871 as the eastern terminus of the Metropolitan District Railway. Today, Mansion House is served by the Circle and District lines. It is between Blackfriars and Cannon Street stations and it is in fare zone 1. The station is located at the junction of Queen Victoria Street and Cannon Street.

The Metropolitan District Railway, also known as the District Railway, was a passenger railway that served London, England, from 1868 to 1933. Established in 1864 to complete an "inner circle" of lines connecting railway termini in London, the first part of the line opened using gas-lit wooden carriages hauled by steam locomotives. The Metropolitan Railway operated all services until the District Railway introduced its own trains in 1871. The railway was soon extended westwards through Earl's Court to Fulham, Richmond, Ealing and Hounslow. After completing the inner circle and reaching Whitechapel in 1884, it was extended to Upminster in Essex in 1902.