English: Coat of Arms of Runcorn, Cheshire, England, granted 30th October 1956 to Runcorn Urban District Council.

Motto 'NAVEM MERCIBUS IMPLERE' - Fill the ship with goods.

The gold background represents prosperity and commerce, with a base of four blue and white waves for the four waterways which have played a major part in the life of the town at different times - the Mersey, the Bridgewater Canal, Manchester Ship Canal and Weaver Navigation. The ship upon the waves was suggested by the original device of the Council, which flies the ancient flag of England and has a wheatsheaf from the arms of Cheshire, which also appears in the arms of the Cholmondeley Earls of Rocksavage. The red chief suggests other important industries - the old sandstone quarrying industry and the fires of modern engineering plants. The two ancient flaying-knives, the symbol of St. Bartholomew, the patron saint of tanners, represent the leather industry and stand between two heraldic fountains signifying water, chemicals, brine and wells. The red chief stretching over the ship also suggests Runcorn's bridges.

The main colours of the mantling, blue and gold, are the Cheshire liveries and the red mural crown represents Halton Castle. The black lion is from the arms of the Savage family of Clifton and Rock Savage and is supporting a crozier for Norton Priory, from which hangs a shield of the arms of William Fitznigel, the Baron of Halton in Norman times. The crown worn by the lion indicates the reversion to the Crown of the ancient Barony of Halton.

The motto is a classical quotation from Juvenal.

ARMS: Or on a Base barry wavy of four Azure and Argent a Lymphad proper flying Flags and Pennon of St. George and the sail also Azure charged with a Garb Gold on a Chief Gules two Flaying Knives in saltire proper handles Or between as many Fountains.

CREST: Out of a Mural Crown Gules a demi-Lion Sable crowned with an Ancient Crown and supporting an Abbot's Crozier Or pendant therefrom by the guige an Escutcheon also Gules charged with four Fusils conjoined in pale each fesswise Or.