Prof William Johnson Sollas PGS FRS FRSE LLD (30 May 1849 – 20 October 1936) was a British geologist and anthropologist. After studying at the City of London School, the Royal College of Chemistry and the Royal School of Mines he matriculated to St. John's College, Cambridge, where he was awarded First Class Honours in geology. After some time spent as a University Extension lecturer he became Lecturer in Geology and Zoology at University College, Bristol in 1879, where he stayed until he was offered the post of Professor of Geology at Trinity College, Dublin. In 1897 he was offered the post of Professor of Geology at the University of Oxford, which he accepted.