List of Famous people who died in 1931

Sir William Hart Dyke, 7th Baronet PC, DL, JP was an English Conservative politician and tennis pioneer.

Louis Billot was a French Jesuit priest and theologian. He became a cardinal in 1911 and resigned from that status in 1927, the only person to do so in the twentieth century.

Xiang Zhongfa was one of the early senior leaders of the Communist Party of China (CPC).

Albert Abraham Michelson FFRS HFRSE was an American physicist known for his work on measuring the speed of light and especially for the Michelson–Morley experiment. In 1907 he received the Nobel Prize in Physics, becoming the first American to win the Nobel Prize in a science. He was the founder and the first head of the physics department of the University of Chicago.

Nicolae Constantin Paulescu was a Romanian physiologist, professor of medicine, and politician, most famous for his work on diabetes, including patenting pancreine. The "pancreine" was an extract of bovine pancreas in salted water, after which some impurites were removed with hydrochloric acid and sodium hydroxide. Paulescu was also, with A. C. Cuza, co-founder of the National Christian Union and later, of the National-Christian Defense League in Romania.

Henrique Lopes de Mendonça was a Portuguese poet, playwright, novelist, novella and short story writer, and naval officer. He wrote several plays, and with his friend, the composer Alfredo Keil, he wrote the lyrics of the future Portuguese national anthem, A Portuguesa, which was officially adopted in 1911.

Solon Irving Bailey was an American astronomer and discoverer of the main-belt asteroid 504 Cora, on June 30, 1902.

Alfred Grotjahn was a German physician, social hygienist, eugenicist, journalist-author and, for three years between 1921 and 1924, a Member of the Reichstag in the recently launched German republic. He became celebrated as a pioneer, and among admirers an inventor, of the discipline of "social hygiene" which, in Germany, was not merely an ephemeral euphemism for the sociological study of sexually transmitted diseases, but embraced a series of topics along the interface between sociology and medicine. When first he publicised his ideas at the start of the twentieth century he encountered a barrage of opposition from the powerful and increasingly politicised Eugenics lobby, but during the next three decades some of his own thinking came closer to that of the eugenicists: by the time he died he was sometimes identified as part of the eugenics movement. After he died, many of his ideas remained mainstream in Germany and among some medical scholars in North America through the 1930s, but by 1945 they had become discredited across Europe, alongside those of the eugenics movement itself, by their association with the Hitlerite atrocities. Within Germany, despite a few of his ideas turning up as government policy, Grotjahn was in the short term airbrushed out of history during the 1930s on account of his Jewish provenance. His son emigrated to the United States in 1937, ending up in Los Angeles, where he acquired notability on his own account as a psychoanalyst.

Karl or Carl Fritz was a German Roman Catholic clergyman. From 28 October 1920 until his death he served as Archbishop of Freiburg.

Frederick William Lehmann was a prominent American lawyer, politician, United States Solicitor General, and rare book collector.