Henry Crozier Keating Plummer FRS[1] FRAS (24 October 1875 – 30 September 1946) was an English astronomer.
He gained his education at St. Edward's School and then Hertford College at Oxford University.
After studies in physics, he became a lecturer at Owen's College, Manchester, instructing in mathematics.
In 1912, he was appointed to the position of Andrews Professor of Astronomy at Trinity College, Dublin, which carried with it the title of Royal Astronomer of Ireland.
He also made studies of the history of science, and served on the Royal Society committee that was formed to publish the papers of Sir Isaac Newton.