圣托里尼（希腊文：Σαντορίνη）是在希腊大陆东南200公里的爱琴海上由一群火山组成的岛环，位于北纬 36.40° —东经 25.40°。圣托里尼岛环上最大的一个岛也叫圣托里尼岛，别名锡拉岛（Θήρα）。圣托里尼岛位于基克拉泽斯群岛的最南端，面积约73平方公里，人口约一万四千余人，多为希腊人。“圣托里尼”是十三世纪时威尼斯人所命名的，起源于圣·爱莲（意大利语：Santa Irene）；在此前这个岛称为锡拉岛、卡利斯提（Καλλίστη，在古希腊语意为“最美”）或斯特隆基里（Στρογγύλη）。岛上建筑蓝白相间，衬以蔚蓝大海，美不胜收，是著名旅游胜地。

Santorini (Greek:Σαντορίνη, pronounced [sandoˈrini]), classically Thera (English pronunciation /ˈθɪərə/), and officially Thira (Greek: Θήρα [ˈθira]), is an island in the southern Aegean Sea, about 200 km (120 mi) southeast of Greece's mainland. It is the largest island of a small, circular archipelago which bears the same name and is the remnant of a volcanic caldera. It forms the southernmost member of the Cyclades group of islands, with an area of approximately 73 km (28 sq mi) and a 2011 census population of 15,550. The municipality of Santorini includes the inhabited islands of Santorini and Therasia and the uninhabited islands of Nea Kameni, Palaia Kameni, Aspronisi, and Christiana. The total land area is 90.623 km (34.990 sq mi). Santorini is part of the Thira regional unit.