The town of Rothesay is the principal town on the Isle of Bute, in the council area of Argyll and Bute, Scotland. It can be reached by ferry from Wemyss Bay which offers an onward rail link to Glasgow. At the centre of the town is Rothesay Castle, a ruined castle which dates back to the 13th century, and which is unique in Scotland for its circular plan. Rothesay lies along the coast of the Firth of Clyde.

Rothesay was the county town of the former county of Bute, which included the islands of Great Cumbrae, Little Cumbrae and Arran. The former county buildings, now partially closed down, overlook the castle.

During the Victorian era, Rothesay developed as a popular tourist destination. It became hugely popular with Glaswegians going "doon the watter" (lit: down the water, where the 'water' in question is the Firth of Clyde), and its wooden pier was once much busier with steamer traffic than it is today. Rothesay was also the location of one of Scotland's many hydropathic establishments during the 19th century boom years of the Hydropathy movement. The town also had an electric tramway - the Rothesay and Ettrick Bay Light Railway - which stretched across the island to one of its largest beaches. However, this closed in the mid-1930s. The centre of activities was the Winter Gardens building (built 1923) which played host to some of the best known music hall entertainers of the day.

From the 1960s onwards, with the advent of cheap foreign package holidays, Rothesay's heyday was largely over. The Winter Gardens closed and lay derelict for many years. However in the 1990s, it was redeveloped and is now a tourist information and exhibition centre.