The Kamchatka Peninsula (Russian: полуостров Камчатка, romanized: Poluostrov Kamchatka, pronounced [pəlʊˈostrəf kɐmˈt͡ɕætkə]) is a 1,250-kilometre-long (777 mi) peninsula in the Russian Far East, with an area of about 270,000 km² (104,248 sq mi). The Pacific Ocean and the Sea of Okhotsk make up the peninsula's eastern and western coastlines, respectively. Immediately offshore along the Pacific coast of the peninsula runs the 10,500-metre-deep (34,449 ft) Kuril–Kamchatka Trench.

The Kamchatka Peninsula, the Commander Islands, and the Karaginsky Island, constitute the Kamchatka Krai of the Russian Federation. The vast majority of the 322,079 inhabitants are ethnic Russians, although about 13,000 are Koryaks (2014). More than half of the population lives in Petropavlovsk-Kamchatsky (179,526 in 2010) and nearby Yelizovo (38,980). The Kamchatka peninsula contains the volcanoes of Kamchatka, a UNESCO World Heritage Site.