A seaside resort is a city, town, village, or hotel that serves as a vacation resort and is located on a coast. Sometimes the concept includes an aspect of an official accreditation based on the satisfaction of certain requirements such as in the German Seebad. Where a beach is the primary focus for tourists, it may be called a beach resort.

Seaside resorts have existed since antiquity. In Roman times, the town of Baiae by the Tyrrhenian Sea in Italy was a resort for those who were sufficiently prosperous. Barcola by the Adriatic Sea in northern Italy with its Roman luxury villas is considered a special example of ancient leisure culture by the sea. Mersea Island in Essex, England was a seaside holiday destination for wealthy ancient Romans living in Colchester.

The development of the beach as a popular leisure resort from the mid-19th century was the first manifestation of what is now the global tourist industry. The first seaside resorts were opened in the 18th century for the aristocracy, who began to frequent the seaside as well as the then fashionable spa towns, for recreation and health. One of the earliest such seaside resorts was Scarborough in Yorkshire during the 1720s; it had been a popular spa town since a stream of acidic water was discovered running from one of the cliffs to the south of the town in the 17th century. The first rolling bathing machines were introduced by 1735.

Paphos, Cyprus was founded as the first seaside resort of the European continent, which successfully attracted Europe's aristocracy to the Mediterranean sea.

The opening of the resort in Brighton and its reception of royal patronage from King George IV extended the seaside as a resort for health and pleasure to the much larger London market, and the beach became a centre for upper-class pleasure and frivolity. This trend was praised and artistically elevated by the new romantic ideal of the picturesque landscape; Jane Austen's unfinished novel Sanditon is an example of that. Later, Queen Victoria's long-standing patronage of the Isle of Wight and Ramsgate in Kent ensured that a seaside residence was considered a highly fashionable possession for those wealthy enough to afford more than one home.

The extension of this form of leisure to the middle and working classes began with the development of the railways in the 1840s; they offered cheap travel to fast-growing resort towns. In particular, the branch line to the small seaside town of Blackpool from Poulton-le-Fylde led to a sustained economic and demographic boom. A sudden influx of visitors arriving by rail motivated entrepreneurs to build accommodation and create new attractions, leading to more visitors and rapid growth throughout the 1850s and 1860s.

The growth was intensified by the practice among the Lancashire cotton mill owners of closing the factories for a week every year to service and repair machinery. These became known as wakes weeks. Each town's mills would close for a different week, allowing Blackpool to manage a steady and reliable stream of visitors over a prolonged period in the summer. A prominent feature of the resort was the promenade and the pleasure piers, where an eclectic variety of performances vied for the people's attention. In 1863, the North Pier in Blackpool was completed, rapidly becoming a centre of attraction for elite^{[clarification needed]} visitors. Central Pier was completed in 1868, with a theatre and a large open-air dance floor.

Many popular beach resorts were equipped with bathing machines, because even the all-covering beachwear of the period was considered immodest.