Dallastown is a borough in York County, Pennsylvania, United States. The population was 4,049 at the 2010 census.
Dallastown was named after George M. Dallas of Philadelphia (Vice President of the United States during the Polk administration) during the presidential campaign of 1844. Dallastown was incorporated April 1866.
President Lyndon Johnson visited Dallastown in 1966 as part of the town's centennial celebration.