Frederick Wilfrid ("Wilf") Lancaster (September 4, 1933 – August 25, 2013) was a British-American information scientist. He immigrated to the USA in 1959 and worked as information specialist for the National Library of Medicine in Bethesda, Maryland from 1965–68. He was a professor at the University of Illinois, Urbana from 1972-92 and professor emeritus from 1992-2013. He continued as an honored scholar after retirement speaking on the evolution of librarianship in the 20th and 21st century. Lancaster made notable achievements with early online retrieval systems, including evaluation studies of MEDLARS. He published broadly in Library and Information Science over a period of four decades and continuously emerged as a visionary leader in the field, where research, writing, and teaching ear