Sir Patrick Playfair Laidlaw (1881–1940) was a British virologist.
He was one of the scientists working at the Medical Research Council at Mill Hill who first isolated influenza virus from humans. This happened when ferrets they were working on to develop a distemper vaccine caught influenza from one of the scientists in the laboratory.
He was knighted in the 1935 Birthday Honours for distinguished service to medical science.
- Medical science at www.hero.ac.uk
- Smith W, Andrewes CH, Laidlaw PP. A virus obtained from influenza patients. Lancet. 1933;2:66–8.
- Distemper and Influenza at Mill Hill by Rick Carver and John Skehel from Mill Hill Essays 2000