Peter Fenelon Collier (December 12, 1849 – April 23, 1909) was the founder of the publishing company P.F. Collier & Son, and in 1888 founded Collier's Weekly. P.F. Collier & Son Company published the encyclopedias Collier's Cyclopedia of Social and Commercial Information (1883, Editor Nugent Robinson), the New American Encyclopedia of Social and Commercial Information (1908, Editor James E. Homans) and the 10 volume Collier's New Encyclopedia (1921, 1926, 1928, Editor Francis J. Reynolds, Chairman William A. Neilson).
He was born in Myshall, County Carlow, Ireland, on December 12, 1849, to Robert Collier and Catherine Fenelon. He emigrated to Dayton, Ohio, United States, in 1866 when he was seventeen years old. He attended St. Mary's Seminary in Cincinnati for four years. He then worked for Sadler and Company, a publisher of schoolbooks. With $300 that he saved as a salesman, he bought the printing plates to Father Burke's Lectures. In a single year, his sales were $90,000. In July 1873 he married Catherine Dunne.