Nevil Vincent Sidgwick FRS[1] (8 May 1873 – 15 March 1952) was an English theoretical chemist who made significant contributions to the theory of valency and chemical bonding.

[1] On the return journey, via Penang, in November 1914, a fellow passenger on the Kashima Maru was the astronomer and physicist Professor A S Eddington.

[1] In 1927, he proposed the inert pair effect which describes the stability of heavier p-block atoms in an oxidation state two less than the maximum.

In 1940 his Bakerian lecture with Herbert Marcus Powell correlated molecular geometry with the number of valence electrons on a central atom.

It is a wonderful place, with a great deal of good work going on, and everybody is most kind, so that I can see that I am going to have a very pleasant time here.”[1] His stay at Ithaca was followed by a 10,000 mile trip to the West and back via Yellowstone National Park, Buffalo, Ottawa and Quebec.

He was given a warm reception at the American Chemical Society meeting in New York in early September, having earlier had the chance to visit Oak Ridge National Laboratory.

Nevil Vincent Sidgwick died, unmarried, at the Acland Nursing Home, Oxford, on 15 March 1952, leaving effects worth £67,000.