North Woodbury Township is located in the southeast corner of Blair County, with Bedford County to the south and east, and a small portion of Huntingdon County to the northeast. The township completely surrounds the borough of Martinsburg. Census-designated places in the township include Fredericksburg (also known as “Clover Creek”), Millerstown, Henrietta, Curryville, Martinsburg Junction, Spring Drive Mobile Home Park, and Homewood at Martinsburg.
According to the United States Census Bureau, the township has a total area of 20.8 square miles (53.9 km2), all of it land.
North Woodbury Township is to the south of Woodbury Township, Blair County. This geographical quirk is because the township was formerly part of Bedford County, and is indeed north of Woodbury Township, Bedford County. The eastern border of the township follows the ridgecrest of Tussey Mountain.
A portion of Pennsylvania State Game Lands Number 73 is located on the eastern border of the township.