Shirahama is a town located in the Nishimuro District of Wakayama Prefecture, Japan, situated on the Pacific coast of the Kii Peninsula in the southwestern part of the region. It serves as a significant municipal entity within this coastal area, characterized by its proximity to the ocean and its role as a local administrative center. The town covers a total area of 200.98 square kilometres, positioning it as a distinct geographic unit within the broader prefectural landscape.

The area was historically part of ancient Kii Province, with hot springs in the region documented in the Nihon Shoki and utilized since ancient times. The modern municipality traces its administrative origins to April 1, 1889, when the village of Setokanayama was established under the new municipal system. Local volunteers began developing the seaside area in competition with older mountain springs in 1919, successfully drilling for a hot spring source by 1922. The village was promoted to town status on March 1, 1940, and later expanded through annexations in 1955, 1958, and 2006.

The town is defined by its natural geography and developed tourist infrastructure along the coast. A primary feature is its crescent-shaped white-sand beach, which gave the town its name meaning white beach or white bay. Notable landmarks include Engetsu-tō, a natural arch off the coast, and Sandanbeki, cliffs fifty meters high where pirate dwellings remain visible. The area also features the Nanki-Shirahama Adventure World theme park and the Kumano Kodo pilgrimage route, alongside the historic Minakata Kumagusu Museum.

Shirahama functions primarily as a resort town, having been promoted as a honeymoon destination after World War II and gaining popularity in the 1960s following rail connections to Osaka. The Nanki-Shirahama Onsen is celebrated as one of Japan's top hot springs, with waters cooled by ocean waves. Summer brings nightly fireworks on the beach, while the town maintains sister city relationships with Gwacheon in South Korea and Honolulu in Hawaii, reflecting its international appeal as a coastal retreat.

As of 31 October 2021, the town had an estimated population of 20,704 in 11,024 households, with a density of 100 persons per square kilometre. The economy relies on tourism, commercial fishing, and hothouse flower production. Access is provided via JR West’s Kisei Main Line, the Kisei Expressway, and Nanki-Shirahama Airport, which offers daily flights to Tokyo. The humid subtropical climate features warm summers averaging 27.6 °C in August and cool winters, with July being the wettest month due to significant annual rainfall.