David Colquhoun is a British pharmacologist at University College London (UCL). He has contributed to the general theory of receptor and synaptic mechanisms, and in particular the theory and practice of single ion channel function. He held the A.J. Clark chair of Pharmacology at UCL from 1985 to 2004, and was the Hon. Director of the Wellcome Laboratory for Molecular Pharmacology. He was elected a Fellow of the Royal Society (FRS) in 1985 and an honorary fellow of UCL in 2004. Colquhoun runs the website DC's Improbable Science, which is critical of pseudoscience, particularly alternative medicine, and managerialism. He was critical of Tim Hunt following the controversies of the 2015 World Conference of Science Journalists in Seoul.