- James Parkinson was born on 11 April 1755 in Shoreditch, London, England.
- He was the son of John Parkinson, an apothecary and surgeon practising in Hoxton Square in London.
- He was the oldest of three siblings, which included his brother William and his sister Mary Sedgewood.
- On 21 May 1783, he married Mary Dale, with whom he subsequently had eight children; two did not survive past childhood. Soon after he was married, Parkinson succeeded his father in his practice in 1 Hoxton Square.
- In 1784 Parkinson was approved by the City of London Corporation as a surgeon.
- In 1812 Parkinson assisted his son with the first described case of appendicitis in English, and the first instance in which perforation was shown to be the cause of death.
- Parkinson was the first person to systematically describe six individuals with symptoms of the disease that bears his name. Jean-Martin Charcot coined the term "Parkinson's disease" some 60 years later.
- Parkinson belonged to a school of thought, Catastrophism, that concerned itself with the belief that the Earth's geology and biosphere were shaped by recent large-scale cataclysms.
- He died on 21 December 1824 after a stroke that interfered with his speech, bequeathing his houses in Langthorne to his sons and wife and his apothecary's shop to his son, John.
- His collection of organic remains was given to his wife and much of it went on to be sold in 1827, a catalogue of the sale has never been found.
- He was buried at St. Leonard's Church, Shoreditch and Parkinson's life is commemorated with a stone tablet inside the church of St Leonard's, Shoreditch, where he was a member of the congregation; the exact site of his grave is not known and his body may lie in the crypt or in the churchyard.
- There is no known portrait of him: a photograph, sometimes published and identified as of him, is of a dentist of the same name, but this James Parkinson died before photography was invented.