The first mention in historical documents is in the late thirteenth century. Uckfield developed as a stopping-off point on the pilgrimage route between Canterbury, Chichester and Lewes. The settlement began to develop around the bridging point of the river, including the locally famous Pudding Cake Lane where travellers visited a public house for slices of pudding cake; and the 15th-century Bridge Cottage, the oldest house still standing in Uckfield, now a museum. The town developed in the High Street and in the New Town areas (the latter to the south of the original town centre).

The Eversfield family, who later became prominent in Sussex history, giving their name to the prime waterfront street of St Leonards-on-Sea, first settled in Uckfield from their Surrey beginnings. The family, who later owned the mansion Denne Park in Horsham, which they represented in Parliament, acquired a large fortune through marriage, real estate acquisition and iron foundering. Their climb to wealth and prominence was a heady one: in fifteenth-century Sussex they were described as ‘yeomen’, but within a generation they were already among the first rank of Sussex gentry.