Norrisville is an unincorporated community in Harford County, Maryland, just south of the Pennsylvania state line in the extreme northwest section of the county. It is primarily a farming community full of rolling hills and small valleys, and is part of the Deer Creek watershed. The area is served by two state roads, Maryland routes 23 and 136. A demographic profile estimates that the Norrisville area had a population of 2,931 as of 2000. It lies at an elevation of 741 feet (226 m).