Gerald Beresford Whitham (13 December 1927 – 26 January 2014) was a British–born American applied mathematician and the Charles Lee Powell Professor of Applied Mathematics (Emeritus) of Applied & Computational Mathematics at the California Institute of Technology. He received his Ph.D. from the University of Manchester in 1953 under the direction of Sir James Lighthill. He is known for his work in fluid dynamics and waves.