Kingswear is not mentioned in the Domesday Book, but it is believed that Kingston, which is above Kingswear, dates from Saxon times, with evidence of Stone Age settlers. The first documentary mention of Kingswear was c.1170 when William de Vinci gave the local church half of the land.

It is not clear why Dartmouth, on the opposite side of the river Dart, developed so much more than Kingswear. Travellers arriving by sea preferred Kingswear as a landing place on their way to the tomb of Thomas à Beckett in Canterbury. This is why the parish church is dedicated to St Thomas of Canterbury. The church was rebuilt in 1847.

Kingswear railway station was opened on 16 August 1864 by the Dartmouth and Torbay Railway, and the Royal Dart Hotel provided accommodation for passengers waiting to sail to South Africa and elsewhere.

The first Kingswear Regatta was held around 1890.

During the Second World War the hotel became HMS Cicala and headquarters of the British 15th Destroyer Flotilla. Journeys were made from there to the northern beaches of Brittany, landing agents and equipment for the French Resistance and bringing back escaping allied soldiers and airmen. The Free French Navy operated motor launches and motor torpedo boats from Kingswear and was based in Brookhill, a large house dating from about 1820 on the outskirts of the village.