William van Leckwijck (16 November 1902 – 19 June 1975) was a Belgian mining engineer and geologist.
He worked as surveyor and consultant across Europe for mining companies and became a professor at the University of Leuven from 1964.
Van Leckwijck was born in Antwerp but the family moved to England at the onset of World War I.
He then worked across Europe and North Africa and conducted surveys for a while at Société Ougrée-Marihaye during World War II.
In 1964 he succeeded Theodor Sorgenfrei (1915–1972) as professor of paleontology at the Catholic University of Leuven where he established micropaleontology.