Westgate-on-Sea is a seaside town in northeast Kent, England, with a population of 6,600. It is within the Thanet local government district and borders the larger seaside resort of Margate. Its two sandy beaches have remained a popular tourist attraction since the town's development in the 1860s from a small farming community.

The town is notable for once being the location of a Royal Naval Air Service seaplane base, which defended the Thames Estuary coastal towns during World War I. The town is the subject of Sir John Betjeman's poem, Westgate-on-Sea. Residents have included the 19th century surgeon Sir Erasmus Wilson and former Archbishop of Canterbury William Temple. The artist Sir William Quiller Orchardson painted several of his most well-known pictures while living in Westgate-on-Sea. The British composer Arnold Cooke attended the town's Streete Preparatory School in the early 1900s.

Westgate-on-Sea is bordered by the town of Margate to the east and the village of Birchington-on-Sea to the west. The town is built beside the two sandy bays of St Mildred's Bay and West Bay, which both have a sea wall and groynes to prevent coastal flooding. Chalk cliffs are present in between the bays and either side of the bays. The whole of the northeast Kent coast has been designated a Site of Special Scientific Interest.

The climate in East Kent, the warmest time of the year is July and August, when maximum temperatures average around 21 °C (70 °F). The coolest time of the year is January and February, when minimum temperatures average around 1 °C (34 °F). The average maximum and minimum temperatures are around 1/2 °C higher than the national average.

Transport links include Westgate-on-Sea railway station which is on the Chatham Main Line, which runs between Ramsgate in East Kent and London Victoria. Other stations on this line include Broadstairs, Margate, Herne Bay, Faversham, Gillingham, Rochester and Bromley South. Westgate-on-Sea is around 1 hour and 45 minutes to London by fast-service train. A National Express coach service runs between London Victoria and Ramsgate, and a selection of trains run to London's Cannon Street station, primarily for business commuting. There is a Stagecoach bus service running to neighbouring Birchington and Margate, and a service running between Broadstairs and Canterbury via Westgate-on-Sea. The A28 road runs between Hastings and Margate via Ashford, Canterbury, Birchington and Westgate-on-Sea. 4 miles (6 km) southwest of Westgate-on-Sea, the A28 crosses the A299 road, which leads along North Kent towards London, becoming the M2 motorway at Faversham.

The economy is mainly based around tourism; there are several hotels and guest houses near the seafront, to accommodate the influx of visitors during the summer. The High Street has a variety of shops and services. The elderly population has led to many health and social care jobs at local care homes.

The town has sandy beaches at both St Mildred's Bay and West Bay. The larger of the beaches is at St Mildred's Bay, where it is possible to hire beach huts, deck chairs and jet-skis. The beach is a short distance from tennis courts and a golf putting course. At West Bay, there are many small rock pools, which are popular with children. Each beach has nearby cafés, restaurants and public houses, and a European Blue Flag Award is shared between them due to their cleanliness and safety.