St Leonards-on-Sea is a town and seaside resort in the Borough of Hastings in East Sussex, England. It has been part of the borough since the late 19th century and lies to the west of central Hastings. The original part of the settlement was laid out in the early 19th century as a new town: a place of elegant houses designed for the well-off; it also included a central public garden, a hotel, an archery, assembly rooms and a church. Today's St Leonards has extended well beyond that original design, although the original town still exists within it.

Hastings is a seaside town and borough in East Sussex on the south coast of England, 24 mi (39 km) east of Lewes and 53 mi (85 km) south east of London. The town gives its name to the Battle of Hastings, which took place 8 mi (13 km) to the north-west at Senlac Hill in 1066. It later became one of the medieval Cinque Ports. In the 19th century, it was a popular seaside resort, as the railway allowed tourists and visitors to reach the town. Today, Hastings is a fishing port with the UK's largest beach-based fishing fleet. It has an estimated population of 91,100 as of 2021.