Annex is an unincorporated community and census-designated place in Malheur County, Oregon, United States.

[5] The community is located on the south bank of the Snake River across from Weiser, Idaho; a bridge carrying U.S. Route 95 Spur connects the two.

According to the U.S. Census Bureau, the community has an area of 2.461 square miles (6.37 km2), all of it land.

[10] In 1958, there were 46 students at Weiser High who lived in the Annex and Jefferson school districts.

This Malheur County, Oregon state location article is a stub.