The islands comprising the Taiwan Area under the jurisdiction of the Republic of China (ROC) are classified into various island groups. The island of Taiwan, also known as Formosa, is the largest island and the main component of the ROC-controlled territories. Islands that are claimed by the ROC but not administered, including those administered by the People's Republic of China (PRC), and those disputed with other countries such as the Tiaoyutai Islands (Senkaku Islands) and most of the South China Sea Islands, are excluded from this list.

At the adoption of Additional Articles of the Constitution of the Republic of China in the 1990s, these islands collectively form the "Free area of the Republic of China" or known alternatively as "Taiwan Area", which legally defines the territorial extent under the actual control of the ROC government.

Some Taiwanese islands have various translations in English due to different systems of romanization in Chinese language in use, or derivation of differing linguistic origins from Mandarin, Hokkien, indigenous languages or other foreign languages. Some islands also have different names derived from particular historical periods which remain in use to this day.

There are in total of 168 islands which can be classified into the following geographical units:

Note: The Senkaku Islands, which are controlled by Japan, are disputed by the PRC (People's Republic of China) and the ROC as being a part of Taiwan (known as "Tiaoyutai" in Taiwanese Mandarin). Japan administers the Senkaku Islands as a part of the Ryukyu Islands.

List of Taiwanese islands with over 5 km² of area.

The highly controversial sovereignty disputes over both the Japan-controlled Senkaku Islands and the South China Sea Islands (which are disputed and controlled by several countries) are complex with the disputed status of both Taiwan (the territories outlined in the 1951 Treaty of San Francisco) and the Republic of China (ROC) which controls Taiwan. As the ROC and the People's Republic of China (PRC) still compete their de jure claim as the sole legitimate government of the entire China, they effectively lay claim to the same extent of islands, including the South China Sea Islands and the Senkaku Islands, among others. This makes these disputes multi-layered and therefore virtually impossible to solve by following the guidelines of international law.

The ROC maintains its historical claims to all of the South China Sea Islands. They are also claimed by five other claimants, namely the PRC, Vietnam, the Philippines, Malaysia, and Brunei. The islands within the Pratas and Spratly Islands which remain under the control of the ROC are assigned to Cijin District, Kaohsiung City, thus technically defining these islands to be part of the "Taiwan Area". The United Nations considers the South China Sea to be "international waters" and does not acknowledge any of the South China Sea Islands as "true islands". The acknowledgement of these islands as "true islands" is crucial because the definition of "islands" would justify the creation of an exclusive economic zone around them, which can be used to cut off international shipping lanes and to acquire natural resources such as oil which lie beneath the ocean.