David Crystal, OBE (born 1941 in Lisburn, Northern Ireland, UK) is a linguist, academic and author. He grew up in Holyhead, North Wales, and Liverpool, England where he attended St Mary’s College from 1951.

Crystal studied English at University College London between 1959 and 1962. He was a researcher under Randolph Quirk between 1962 and 1963, working on the Survey of English Usage. Since then he has lectured at Bangor University and the University of Reading. He is currently an honorary professor of linguistics at Bangor. His many academic interests include English language learning and teaching, forensic linguistics, language death, "ludic linguistics" (Crystal’s neologism for the study of language play), English style, Shakespeare, indexing, and lexicography. He is the Patron of the International Association of Teachers of English as a Foreign Language (IATEFL).

David Crystal lives in Holyhead with his wife; he has four grown-up children, his son Ben Crystal is also an author and co-authored two books with his father. Retired from full-time academia, he works as a writer, editor and consultant. Crystal was awarded the OBE in 1995 and became a Fellow of the British Academy in 2000.