John Newlands (born November 26, 1837, London, England—died July 29, 1898, London) was an English chemist whose “law of octaves” noted a pattern in the atomic structure of elements with similar chemical properties and contributed in a significant way to the development of the periodic law.

Newlands studied at the Royal College of Chemistry, London, fought as a volunteer under Giuseppe Garibaldi for Italian unification (1860), and later worked as an industrial chemist. In 1864 he published his concept of the periodicity of the chemical elements, which he had arranged in order of atomic weight. He pointed out that every eighth element in this grouping shared a resemblance and suggested an analogy with the intervals of the musical scale. The “law of octaves,” thus enunciated, was controversial at first but later was recognized as an important generalization in modern chemical theory. Newlands collected his various papers in On the Discovery of the Periodic Law (1884).