The Riau Islands (Indonesian: Kepulauan Riau; Jawi: كڤولاوان رياو) is a province of Indonesia consisting of a group of islands located in the western part of the country. It was established in 2002 after being separated from the neighboring Riau Province. The capital of the province is Tanjung Pinang, while the largest city is Batam. It shares a maritime border with Riau and Jambi to the west, Bangka Belitung Islands to the south, Singapore to the northeast, Malaysia and West Kalimantan to the east, and Vietnam and Cambodia to the north. It comprises a total of 2,408 islands (1,798 having names) scattered between Sumatra, Malay Peninsula, and Borneo including the Riau Archipelago. Situated on one of the world's busiest shipping lanes along the Malacca Strait and the Natuna Sea (South China Sea), the province shares water borders with neighboring countries such as Singapore, Malaysia, and Brunei. The Riau Islands also have relatively large potential mineral resources and energy, as well as marine resources.

The Riau Islands have played a significant role in the maritime history and civilization of the Nusantara region. Between the 7th and 13th centuries, the area was influenced by the powerful Srivijaya Empire, a major maritime kingdom that controlled trade routes along the Malacca Strait. Evidence of Srivijaya's influence in the Riau Islands can be seen from the discovery of the Pasir Panjang Inscription [id] in Karimun Regency, which shows the existence of religious practices through Buddha's footprints, indicating early settlement and the spread of Buddhism long before the arrival of Islam.

After the decline of Srivijaya, the Riau Islands became part of the Bentan Kingdom around 1100 AD, with Raja Iskandar Syah as one of its most notable rulers.In the next period, The Riau Islands became part of the Johor Sultanate, which was later partitioned between the Dutch East Indies and British Malaya after the Anglo-Dutch Treaty of 1824, in which the archipelago fell under Dutch influence. A Dutch protectorate, the Riau-Lingga Sultanate, was established in the region between 1824 and 1911 before being directly ruled by the Dutch East Indies. The archipelago became a part of Indonesia following the occupation of the Japanese Empire (1942–1945) and the Indonesian National Revolution (1945–1949). The Riau Islands separated from the province of Riau in September 2002, becoming Indonesia's third-youngest province.

A free trade zone of the Indonesia–Malaysia–Singapore Growth Triangle, the Riau Islands has experienced rapid industrialisation since the 1970s. The Riau Islands is one of the country's most prosperous provinces, having a GDP per capita of Rp 72,571,750 (US$8,300.82) as of 2011, the fourth highest among all provinces in Indonesia after East Kalimantan, Jakarta and Riau. In addition, as of 2018, the Riau Islands has a Human Development Index of 0.748, also the fourth highest among all provinces in Indonesia after Jakarta, Special Region of Yogyakarta and East Kalimantan.

The population of the Riau Islands is heterogeneous and is highly diverse in ethnicity, culture, language and religion. The province is home to different ethnic groups such as the Malays, Tionghoa, Javanese, Minangkabau and others. Economic rise in the region has attracted many immigrants and workers from other parts of Indonesia. The area around Batam is also home to many expatriates from different countries. Approximately 80% of these are from other Asian countries, with most of the westerners coming from the United Kingdom, rest of Europe, as well as Australia and the United States. The province also has the second largest number of foreign tourist arrivals in Indonesia, after Bali.

There are several possible origins of the word riau. The first possible origins is that riau is derived from the Portuguese word rio, which means river. After the fall of the Malacca Sultanate in the early 16th century, the remaining Malaccan nobles and subjects fled from Malacca to mainland Sumatra while being pursued by the Portuguese. The Portuguese is believed to have reached as far as the Siak River.

The second version claims that riau comes from the word riahi which means sea water. The word is allegedly derived from the figure of Sinbad al-Bahar in the book of the One Thousand and One Nights.

Another version is that riau is derived from the Malay word riuh, which means crowded, frenzied working people. This word is believed used to reflect the nature of the Malay people in present-day Bintan. The name is likely to have become famous since Raja Kecil moved the Malay kingdom center from Johor to Ulu Riau in 1719. This name was used as one of the four main sultanates that formed the kingdoms of Riau, Lingga, Johor and Pahang. However, as the consequences of the Anglo-Dutch Treaty of 1824 between the Netherlands and United Kingdom, the Johor-Pahang sultanates fell under British influence, while the Riau-Lingga sultanates fell under Dutch influence.