Old Lycoming Township is a township in Lycoming County, Pennsylvania, United States. The population was 5,508 at the 2000 census. It is part of the Williamsport, Pennsylvania Metropolitan Statistical Area.

Old Lycoming Township, Lycoming County, Pennsylvania was formed on 22 August 1785 as Lycoming Township a part of Northumberland County, Pennsylvania ten years before Lycoming County was formed. The original boundaries of the township ecompassed much of the territory that was previously governed by the Fair Play Men. The land between Lycoming and Pine Creeks was outside of the legal boundaries of Pennsylvania until 1784 and the second Treaty of Fort Stanwix. The Fair Play Men operated a system of self government from 1773 to 1785. Their claims to the land had no legal bearing in the state of Pennsylvania when it was finally legally part of the state. These men had some troubles gaining the title to the land that they had cleared and defended for so long. Some of them were able to keep their lands and others chose to move further west.

In the American Revolutionary War, settlements throughout the Susquehanna Valley, including what is now Old Lycoming Township, were attacked by Loyalists and Native Americans allied with the British. In the early summer of 1778 news came of a group of Native American warriors, perhaps accompanied by Loyalist and British soldiers, heading for the West Branch Susquehanna River Valley to destroy settlements. There were many smaller incidents of violence against settlers, but on 10 June 1778 a party of sixteen settlers were attacked in what is now Williamsport. In what became known as the "Plum Tree Massacre", twelve of the sixteen were killed and scalped, including two women and six children. The Wyoming Valley Massacre occurred on 3 July 1778 (near what is now Wilkes-Barre). This news caused the local authorities to order the evacuation of the whole West Branch valley.

Most of the settlers did not return to their farms until after Sullivan's Expedition had driven off the Indian and Loyalist threat. John McMeens a native of South Carolina was one of the first to return to the area. He had settled along the river in 1776. He fled during the Big Runaway and returned in 1791. McMeens rose to a position of prominence in Lycoming County. He was a county commissioner, state commissioner and served on the initial committee that explored to possibility of building the Pennsylvania Canal that improved navigation on the Susquehanna River. McMeens also represented the area in the Pennsylvania General Assembly from 1814 to 1818.

Derick Updegraff arrived in Lycoming Township from York County in 1787. He settled on land that had previously been improved during the Fair Play Men era. He was not able to claim legal control of his 500 acres until 1793 as the resulty of a law suit over the land filed by the man who had previously claimed it. Updegraff and his sons improved the land by clearing many more acres and building what was one of the largest barns in Lycoming County.

In 1858 Lycoming Township was split into Old Lycoming Township and Lycoming Township. On the 2d of December, 1858, the following decree was made by Judge Jordan: "The court directs that that part of Lycoming township between the river and the division be called Old Lycoming township, and the part between said line and Cogan House and Lewis townships be called Lycoming township."

Today Old Lycoming Township includes the census designated area of Garden View. Garden View serves as a suburb to Williamsport with many family homes and an extensive stretch of commercial and light industrial development along Lycoming Creek Road.

Old Lycoming Township is bordered by Lycoming Township to the north and the eastern border with Loyalsock Township is formed by Lycoming Creek. Old Lycoming Township is bordered by the Newberry section of Williamsport to the south and by Woodward Township to the west.