Martinsburg is a borough in the Morrisons Cove section of Blair County, Pennsylvania, United States. The population was 1,958 at the 2010 census. It is part of the Altoona, PA Metropolitan Statistical Area.
The community was named after John Martin, a pioneer citizen.
Martinsburg is located at 40°18′38″N 78°19′32″W (40.310548, -78.325628).
According to the United States Census Bureau, the borough has a total area of 0.6 square miles (1.6 km2), all of it land.
As of the census of 2000, there were 2,236 people, 892 households, and 544 families residing in the borough. The population density was 3,544.3 people per square mile (1,370.4/km²). There were 924 housing units at an average density of 1,464.6 per square mile (566.3/km²). The racial makeup of the borough was 99.46% White, 0.09% Native American, 0.04% Asian, 0.04% from other races, and 0.36% from two or more races. Hispanic or Latino of any race were 0.36% of the population.
There were 892 households, out of which 26.3% had children under the age of 18 living with them, 49.0% were married couples living together, 9.3% had a female householder with no husband present, and 39.0% were non-families.