Lamar is a census-designated place in Porter Township in southern Clinton County, Pennsylvania, United States. As of the 2010 census the population was 562.The community is located along Pennsylvania Route 64 in southern Clinton County and is bordered on the west by Nittany in Walker Township, Centre County. PA 64 leads northeast 1 mile to Exit 173 on Interstate 80 and 11 miles to Lock Haven, the Clinton County seat, and southwest through Nittany 23 miles to State College.