Hugh Esmor Huxley (25 February 1924 – 25 July 2013) was a British molecular biologist who made important discoveries in the physiology of muscle.

Huxley was the first PhD student of Laboratory of Molecular Biology of the Medical Research Council at Cambridge, where he worked on X-ray diffraction studies on muscle fibres.

During his postdoctoral at Massachusetts Institute of Technology, he, with fellow researcher Jean Hanson, discovered the underlying principle of muscle movement, popularised as the sliding filament theory in 1954.

After 15 years of research, he proposed the "swinging cross-bridge hypothesis" in 1969, which became modern understanding of the molecular basis of muscle contraction, and much of other cellular motility.

He therefore joined Cambridge University to become the first PhD student in a newly formed Laboratory of Molecular Biology, then a small Medical Research Council (MRC) unit founded by Max Perutz and John Kendrew, who supervised him.

Since Cambridge did not have electron microscopy, which began to be used for biological studies at the time, he went to Massachusetts Institute of Technology as a postdoctoral fellow on a Commonwealth Fellowship in late summer of 1952.

Knowing his potential the University College London appointed him to the faculty, and moved there to join Bernard Katz's biophysics department in 1955.

Based on his LMB X-ray diffraction images, the new technique immediately helped him to establish the cross-bridge concept (interaction site of the muscle proteins, myosin and actin).

[7] In 1987 he joined the biology faculty at Brandeis University in Waltham, Massachusetts, where he also served as Director of the Rosenstiel Basic Medical Sciences Research Center, and becoming emeritus from 1997 until his death.

He was among the 43 scientists and philosophers who signed the BHA letter in March 2002 to Prime Minister Tony Blair deploring the teaching of creationism in schools.