Recorded history began in York township in 1736 with the signing of a treaty between the Indians and the Penn Proprietors and with the westward surge of settlers across the Susquehanna River. The early European settlers were of many nationalities including English, German, Scotch, and Irish, all with a common background in farming. The nature of their occupation gave to York County and to York Township a character and a reputation which has lasted to the present day.

York City was laid out in 1741, and the County of York was established eight years later in 1749. Comprising an area of 26.4 square miles or 16,883 acres, York Township was formed in 1753 with relatively few settlers at the time. Thirty years later there were approximately 900 people in the township, most of them living in the southeast sections. these more densely settled portions were incorporated into the boroughs of Dallastown in 1867, Red Lion in 1880 and Yoe in 1893.

Growth of the township proceeded slowly after the initial settlement. The population in 1900 was 2,793 and increased to only 3,590 by 1940. Most of the residents were farmers. Spry, originally know as Innersville, was the only residential area of the township at that time. According to the 2000 census, York Township's population stands at 23,637 and has been growing over the past twenty years at a rate of about 250 people per year.

The transformation of York Township from its then predominately rural nature to its present suburban character began shortly after the end of World War II. At that time large lot, single family detached house subdivisions such as Hillcrest, Hill-N-Dale, Arlington Park and other low-density housing developments began to appear.

In 1959, York Township reorganized from a second class township and became a first class township. This mandated a change in the political structure of the township. Five wards were established, each ward electing one member to the Board of Commissioners.