Sir John Parkinson (10 February 1885, in Thornton-le-Fylde, Lancashire – 1976) was an English cardiologist known for describing Wolff-Parkinson-White syndrome.
Parkinson was educated at University College London, and studied medicine at the University of Freiburg and the London Hospital, qualifying in 1907. He received his M.D. in 1910, and worked as an assistant to Sir James Mackenzie at the London Hospital.
During the First World War he served with the Royal Army Medical Corps, commanding a military cardiology centre in Rouen. After the war he returned to the London Hospital, becoming consultant and head of the cardiology department. He was also consultant to the National Heart Hospital, and was a civilian cardiologist for the Royal Air Force from 1931 to 1956. He was knighted by King George VI in 1948. The first European Congress of Cardiology opened on 10 September 1952 under the chairmanship of Sir John Parkinson.
Sir John had five children of which four were girls. His only son, Robert Parkinson, was one of the 'Channel Dash Heroes' who were killed during the second world war, aged just 19.