Eastern Military District (Swedish: Östra militärområdet, Milo Ö), originally IV Military District (Swedish: IV.

militärområdet) was a Swedish military district, a command of the Swedish Armed Forces that had operational control over Eastern Sweden, for most time of its existence corresponding to the area covered by the counties of Östergötland, Södermanland, Stockholm, Uppsala and Västmanland.

Milo Ö was created in 1966 along with five other military districts as part of a reorganisation of the administrative divisions of the Swedish Armed Forces.

The coat of arms of the Eastern Military District Staff 1983–1991.

Blazon: "Azur, an erect sword with the area letter (Ö - East) surrounded by an open chaplet of oak leaves, all or.