Portal:History of science/Selected anniversaries/May 27
- 1623 - Birth of William Petty, English scientist and philosopher (d. 1687)
- 1781 - Death of Giovanni Battista Beccaria, Italian physicist (b. 1716)
- 1897 - Birth of John Cockcroft, British physicist, Nobel Prize laureate (d. 1967)
- 1907 - Birth of Rachel Carson, American biologist and science writer (d. 1964)
- 1910 - Death of Robert Koch, German physician and Nobel Prize laureate (b. 1843)
- 1914 - Deat of Joseph Swan, English physicist and chemist (b. 1828)
- 1919 - The NC-4 aircraft arrives in Lisbon after completing the first transatlantic flight.
- 1933 - The Century of Progress World's Fair opens in Chicago, Illinois.
- 1987 - Death of John Howard Northrop, American chemist and Nobel Prize laureate (b. 1891)