The district was created in 1907 to cover the ancient parish of Merton.

Since 1894 the parish had been part of Croydon Rural District and was locally governed by a parish council, that was created by the Local Government Act 1894.

The area of the rural district was within the expanding area of London's southern suburbs and as the population increased it became necessary to reform the local government structures.

An urban district was formed covering the same area as the parish.

The motto, "In Libertate Vis", means "Our Strength is our Freedom".