Bertrand Russell (1872-1970)
May 18 English mathematician and philosopher (Nobel 1950), born in Trellech, England
- May 21 Henry Warren, American inventor (Telechon electric clock), born in Boston, Massachusetts
- May 28 Marian Smoluchowski, Polish physicist (pioneer of statistical physics), born in Vorder-Brühl, Austria-Hungary (d. 1917)
- May 31 Charles Greeley Abbot, American astronomer (Solar Constant), born in Wilton, New Hampshire (d. 1973)
- May 31 W. Heath Robinson, English illustrator and cartoonist (Don Quixote), born in Islington, England (d. 1944)