The Coat of Arms was designed by the College of Heralds and granted in 1974 when the Borough, incorporating Eastleigh and seven parishes of the Winchester Rural District Council, was created.
The design combines items from the original Coats of Arms of both the former Borough of Eastleigh and Winchester Rural District Council together with some features of the new Borough.
The design is in a traditional style, and each detail symbolises a particular piece of the Borough's history.
The intertwined Hampshire roses and lilies of St Mary, the patron Saint of the churches at Bishopstoke and South Stoneham, indicate the union of the two parts of the Borough. The lion is a traditional beast in coats of arms.
The naval crown records the Borough's naval connections and the closed knight’s helmet, also a traditional part of a crest, is used for corporate bodies. The mantling represents the cloak which knights wore over their armour.
The Bishop's mitre refers to the connection of the Bishops of Winchester with Bishopstoke, and is placed between two sheaves of corn which symbolise the rural and agricultural nature of the new Borough.
The two narrow black bands on either side of the chequerboard represent railway lines recalling the historical importance of the railway in the old Borough. They also reflect the cable making activities in the town. In between these lines the black and white chequered strip recalls that Eastleigh was once a Manor held by the Chamberlains of the Royal Exchequer. The winged wheel in the centre signifies the theme of progress and transport.
The medieval ship at the bottom of the crest represents the shipbuilding and yachting activities at Bursledon and Hamble.
The motto, although not strictly part of the Coats of Arms, reads, ‘The Welfare of the People is the most important Law’.