Wellersburg is a borough in Somerset County, Pennsylvania, United States. It is part of the Johnstown, Pennsylvania Metropolitan Statistical Area. The population was 176 at the 2000 census.Wellersburg is located at 39°43′51″N 78°51′05″W / 39.730947°N 78.851465°W / 39.730947; -78.851465.According to the United States Census Bureau, the borough has a total area of 0.8 square miles, all of it land.As of the census of 2000, there were 176 people, 84 households, and 51 families residing in the borough. The population density was 223.4 people per square mile. There were 90 housing units at an average density of 114.2 per square mile. The racial makeup of the borough was 98.86% White, and 1.14% from two or more races.There were 84 households out of which 15.5% had children under the age of 18 living with them, 45.2% were married couples living together, 10.7% had a female householder with no husband present, and 38.1% were non-families. 36.