Littlestown is a borough in Adams County, Pennsylvania, United States. The population was 4,434 at the 2010 census. Originally laid out by Peter Klein in 1760, the town was first named "Petersburg". German settlers in the area came to call the town "Kleine Stedtle". As confusion between the town and a neighboring town (also named "Petersburg", now York Springs grew, the town officially changed its name to Littlestown in 1795.