Sir William Ramsay KCB FRS FRSE (/ˈræmzi/; 2 October 1852 – 23 July 1916) was a Scottish chemist who discovered the noble gases and received the Nobel Prize in Chemistry in 1904 "in recognition of his services in the discovery of the inert gaseous elements in air" along with his collaborator, John William Strutt, 3rd Baron Rayleigh, who received the Nobel Prize in Physics that same year for their discovery of argon.

His work in isolating argon, helium, neon, krypton, and xenon led to the development of a new section of the periodic table.

He then undertook practical training with the chemist Thomas Anderson and then went to study in Germany at the University of Tübingen with Wilhelm Rudolph Fittig where his doctoral thesis was entitled Investigations in the Toluic and Nitrotoluic Acids.

In the same year he became the Principal of University College, Bristol, and somehow managed to combine that with active research both in organic chemistry and on gases.

William Ramsay formed pyridine in 1876 from acetylene and hydrogen cyanide in an iron-tube furnace in what was the first synthesis of a heteroaromatic compound.

In August Ramsay told Rayleigh he had isolated a new, heavy component of air, which did not appear to have any chemical reactivity.

[11] During 1893–1902, Ramsay collaborated with Emily Aston, a British chemist, in experiments on mineral analysis and atomic weight determination.

[13] He was appointed a Knight Commander of the Order of the Bath (KCB) in the 1902 Coronation Honours list published on 26 June 1902,[14][15] and invested as such by King Edward VII at Buckingham Palace on 24 October 1902.

He died in High Wycombe, Buckinghamshire, on 23 July 1916 from nasal cancer at the age of 63 and was buried in Hazlemere parish church.