Mordington is an agricultural parish in the extreme south-east of Berwickshire in the Scottish Borders region. It is five miles from Berwick-upon-Tweed and borders Northumberland to the east, and south (where the boundary is the Whiteadder Water), Foulden to the west, and Lamberton to the north. The parish is bisected by the A6105 Berwick to Duns road. The lower part of the parish is covered by the Edrington estate. It is possibly the warmest parish in Scotland; the annual hours of sunshine are said to be almost as high as at Dunbar, which records the most hours in Scotland.
It is said that there was once a Saxon village, dating from the 11th century, in the northern part of the parish but this has long vanished. Originally claimed by Coldingham Priory, the larger part of the parish eventually came into the possession of the de Mordington family who appear to have failed in the male line. Sir Peter de Mordington, knight, son of the deceased Sir William de Mordington, gave a feu to Simon Baddeby of certain lands in neighbouring Lamberton circa 1276.