Sir Arthur William Rucker (or Rücker), KB, FRS (23 October 1848, Clapham Park, London, England – 1 November 1915, Everington at Yattendon in Berkshire) was a British physicist. He gained his BA at Brasenose College, Oxford, in 1871, and was a Fellow there from 1871 to 1876. He was Professor of Physics at Yorkshire College, Leeds from 1874 to 1885, and then at the Royal College of Science from 1886 to 1901, when he left to become Principal of the University of London. He was elected a Fellow of the Royal Society in 1884. He jointly gave the Royal Society's Bakerian Lecture in 1889, and was awarded the Royal Society's Royal Medal in 1891: "For his researches on liquid films, and his contributions to our knowledge of terrestrial magnetism". He served as Secretary of the Royal Society from 1896 to 1901, and was knighted in 1902.

His first wife died in 1878 and he married Thereza, a daughter of Nevil Story-Maskylene, in 1892.