Thomas Shelburne Ferguson (born December 14, 1929) is an American mathematician and statistician. He is a professor emeritus of mathematics and statistics at the University of California, Los Angeles.^[1]

Ferguson was born in Oakland, California and was raised nearby in Alameda, California. He majored in mathematics at the University of California, Berkeley, and completed his Ph.D. there in 1956.^[1] His dissertation had two separately-titled parts, On Existence of Linear Regression in Linear Structural Relations and A Method of Generating Best Asymptotically Normal Estimates with Application to the Estimation of Bacterial Densities; it was supervised by Lucien Le Cam.^[2]

After another year teaching at Berkeley, he moved to the University of California, Los Angeles in 1957.^[1]

Ferguson is the author of:

• Mathematical Statistics: A Decision Theoretic Approach (Academic Press, 1967)^[3]
• A Course in Large Sample Theory (Chapman & Hall, 1996)^[4]
• A Course in Game Theory (World Scientific, 2020)^[5]

His research contributions include the analysis of the "big match" zero-sum game with David Blackwell, a result that eventually led to the proof of existence of equilibrium values for limiting average payoff in all stochastic games; the Ferguson distribution on prior probability; Ferguson's Dirichlet process;^[1] Ferguson's pairing property in the analysis of misère subtraction games;^[1][6] and contributions to the theory of optimal stopping as e.g. co-authored work on Robbins' problem.^[1]

Ferguson was named a Fellow of the Institute of Mathematical Statistics in 1967,^[1] and a Fellow of the American Statistical Association in 1985. He was given the Belgian International Francqui Chair of Science in 1998. A festschrift in Ferguson's honor edited by F. Thomas Bruss and Lucien Le Cam was published in 2000.^[1]

Ferguson married mathematician Beatriz Rossello, and is the father of poker player Chris Ferguson.^[1][7] He has coauthored papers with Chris Ferguson on the mathematics of poker and other games of chance.