William Young (1755-1829) was a Philadelphia bookseller and later a manufacturer at Rockland, Delaware. He was born near Irvine, Scotland, June 27, 1755, to John Young (1730-unknown) and Agnes Wallace Young (1729-1761). He entered the Associate Presbyterian seminary in Scotland and while still a student in about 1779, married Agnes McLaws (1754-1793), the daughter of an Associate Presbyterian family. Young never completed his studies at the seminary, opting instead to try his hand in a career as a book dealer. At the age of twenty-eight, he left Scotland with his wife and son for America, and never returned. The family arrived at Philadelphia in June 1784.

In Philadelphia, Young continued in the business that he knew best, the book trade. Opening a bookshop and printing establishment at his home on the corner of Second and Chestnut Streets, Young prospered. While his business prospered, Young suffered personal loss, including his wife during the great yellow fever epidemic of 1793.

In 1802, Young sold his printing business to William W. Woodward (1769-1837), married Rachel Anderson (1770-1836), a woman fifteen years his junior, and moved his family to a newly built mansion in Rockland, Delaware. In Rockland, he started a paper manufactory, which provided much of the stock used by Woodward in the Philadelphia printing shop. In 1804, Young was awarded a gold medal for developing a new paper. In 1814, the paper mill burned and was reopened as a woolen mill, but Young overextended his financial resources. The woolen mill soon swallowed most of his ready cash, expansion became impossible. Over the years, Young had received large credits and loans from the firm of John McAllister & Son (the son being his own son-in-law), and upon Young's death in 1829 his estate was found to owe the McAllisters over $57,000. With the woolen mill proving unsuccessful, the Youngs returned to Philadelphia in 1816. It was here that Young died on May 12, 1829.