Martinsburg is a borough in the Morrisons Cove section of Blair County, Pennsylvania, United States.

[4] It is part of the Altoona, PA Metropolitan Statistical Area.

[5] According to the United States Census Bureau, the borough has a total area of 0.6 square miles (1.6 km2), all land.

There were 924 housing units at an average density of 1,464.6 per square mile (565.5/km2).

35.9% of all households were made up of individuals, and 20.2% had someone living alone who was 65 years of age or older.