Wrangel Island (Russian: О́стров Вра́нгеля, romanized: Ostrov Vrangelya, ; Chukot: Умӄиԓир, romanized: Umqiḷir, IPA: [umqiɬir], "island of polar bears") is an island of the Chukotka Autonomous Okrug, Russia. It is the 92nd largest island in the world and roughly the size of Crete. Located in the Arctic Ocean between the Chukchi Sea and East Siberian Sea, the island lies astride the 180th meridian. The International Date Line is therefore displaced eastwards at this latitude to keep the island, as well as the Chukchi Peninsula on the Russian mainland, on the same day as the rest of Russia. The closest land to Wrangel Island is the tiny and rocky Herald Island located 60 kilometres (32 nautical miles) to the east. Its straddling the 180th meridian makes its north shore at that point both the northeasternmost and northwesternmost point of land in the world by strict longitude; using the International Date Line instead those respective points become Herald Island and Alaska's Cape Lisburne.

Most of Wrangel Island, with the adjacent Herald Island, is a federally protected nature sanctuary administered by Russia's Ministry of Natural Resources and Environment. In 1976, Wrangel Island and all of its surrounding waters were classified as a "zapovednik" (a "strict nature reserve") and, as such, receive the highest level of protection, excluding virtually all human activity other than conservation research and scientific purposes. In 1999, the Chukotka Regional government extended the protected marine area to 24 nmi (44 km) offshore. As of 2003, there were four rangers who reside on the island year-round, while a core group of about 12 scientists conduct research during the summer months. Wrangel Island was home to the last surviving population of woolly mammoths, with radiocarbon dating suggesting the species persisted on the island until around 4,000 years ago (2000 BC).

Captain Thomas Long named Wrangel Island for Baron Ferdinand von Wrangel, who was a Baltic German explorer and Admiral in the Imperial Russian Navy. Captain Long, published in The Honolulu Advertiser, November 1867: