Thomas David Spearman (born 1937, known as David Spearman) is an Irish mathematical physicist who is Fellow Emeritus of Trinity College Dublin (TCD), where he spent his career and at various times served as head of the department of pure and applied mathematics, bursar, vice provost and pro-chancellor. He was Professor of Natural Philosophy at TCD from 1966 to 1997. He is the author of 400 years of Mathematics at TCD (1592–1992).