Kautokeino, in North Sami Guovdageaidnu (Kven and Finnish: Koutokeino), is a municipality in Finnmark in northern Norway. The municipality is located on the Finnmarksvidda and borders Finland (Enontekis in the south and southwest and Inari in the southeast), and in Norway to Nordreisa in the west, Kvænangen in the northwest, Alta in the north and Karasjok in the east. Kautokeino is the country's largest municipality in area, almost as large as the next two combined, and about a quarter of Denmark's area. The administrative center of the municipality is the town of Kautokeino.

The origin of the Norwegian name Kautokeino is the Finnish / Kven name Koutokeino which in turn is a loan from the North Sami name Guovdageaidnu; the names are spelled differently for the same name. The North Sami and Norwegian names are equal. Kautokeino is considered the cultural headquarters of the North Sámi area, and around 90% of the inhabitants speak Northern Sámi. Kautokeino was the first and for a long time the only municipality in Norway that equated Sami with Norwegian in public administration. The municipal coat of arms is a gold avvu with a blue background.

The municipality is home to a number of Sami cultural and educational institutions. It is Norway's largest Sami municipality and largest reindeer husbandry municipality. Kautokeino has been the center of, among other things, the Kautokeino uprising in 1852 and the Alta – Kautokeino development.