Combinatorics is an active research group with interests in Algebraic, Enumerative, Geometric, Probabilistic, Extremal and Arithmetic Combinatorics, and adjacent areas such as Discrete and Computational Geometry and Graph Theory.  It also runs a weekly Combinatorics Seminar, meeting Thursdays, with large attendance from graduate students, postdocs and permanent faculty.

History of Combinatorics at UCLA by Bruce Rothschild