Øyvinn Øi (19 June 1901 in Hadsel Municipality in Vesterålen – 9 April 1940) was a Norwegian military officer during the outbreak of the Second World War.

[1] After his examen artium Øi took an officer exam attending the Norwegian Military Academy.

[2] In this lecture, Øi stated that Norway had inadequate defences and was vulnerable to a foreign attack.

This caused a stir in some groups, especially the social democrat newspaper Arbeiderbladet, which came close to accusing him of treason.

Øi was killed on the same day at a road block set up by German forces at Grorud.