Kråkerøy is an island and a former municipality in Østfold county, Norway.
The island of Kråkerøy was separated from Glemmen as a municipality of its own January 1, 1908. At that time Kråkerøy had a population of 3,311. The rural municipality was (together with Borge, Onsøy and Rolvsøy) merged with the city of Fredrikstad January 1, 1994. Prior to the merger Kråkerøy had a population of 7,445.
In 1948 Kråkerøy was the site of the Kråkerøy speech by then Prime Minister Einar Gerhardsen, which became an important part of Norwegian political history.