Ialysos is a town and former municipality located on the island of Rhodes within the Dodecanese region of Greece. Situated on the northwestern coast, it lies approximately eight kilometres west of Rhodes Town, the island's capital. Since the 2011 local government reform, the area functions as a municipal unit within the larger municipality of Rhodes. It holds the distinction of being the second-largest town on the island, covering a land area of 16.7 square kilometres, which is noted as the smallest among all municipal units on Rhodes.

The modern settlement is built near the site of the ancient Doric polis of Ialysus, historically significant as the homeland of the famous boxer Diagoras of Rhodes and poet Timocreon. Before 1976, the town was officially known as Trianta, a name that remains in use by some official sources for the town itself, while Ialysos typically refers to the municipal unit. Unofficial usage often applies Ialysos to both the town and the wider area. The region has evolved from a small village into a major suburban district and tourist destination over recent decades.

The area is defined by its coastal geography and archaeological heritage, including the hill of Filerimos which hosts remains of the temple of Zeus and Athena Poliada alongside Byzantine fortifications. A 14th-century Church of the Knights dedicated to the Virgin Mary of Filerimos stands nearby, accessible via a path lined with cypress trees. The municipal unit includes the seaside resort village of Ixia, situated between Ialysos and Rhodes Town, featuring long narrow beaches with sand and pebbles that attract significant tourism.

Ialysos serves as a popular resort destination known for its blue waters, organized beaches, and mild climate with pleasant summers. The location is particularly noted for windsurfing due to ideal wind conditions on the northwestern coast, hosting important international competitions. Visitors engage in water sports at centres renting boards and jet-skis, shop along the beach strip in Ixia, and enjoy spectacular sunsets. The area also supports local sports teams, including a football club competing in the Gamma Ethniki.

The population of the municipal unit was recorded as 12,717 in 2021, reflecting growth from earlier estimates that placed it around 13,000 or 12,000 in previous years. The local economy is heavily influenced by tourism, with numerous hotels and resorts located along the coast, including establishments in Ixia and near Trianta Beach. Access is facilitated by Diagoras International Airport, located roughly 14 kilometres to the southwest of Ixia, providing connectivity for the region's visitors and residents alike.