Hans von Euler-Chelpin, German-Swedish biochemist and academic, Nobel Prize laureate (born 1863)

Hans Karl August Simon Euler-Chelpin, since 28 July 1884 von Euler-Chelpin, was a German-born Swedish biochemist. He won the Nobel Prize in Chemistry in 1929 with Arthur Harden for their investigations on the fermentation of sugar and enzymes. He was a professor of general and organic chemistry at Stockholm University (1906–1941) and the director of its Institute for organic-chemical research (1938–1948). Euler-Chelpin was distantly related to Leonhard Euler. He married chemist Astrid Cleve, the daughter of the Uppsala chemist Per Teodor Cleve. In 1970, their son Ulf von Euler, was awarded the Nobel Prize in Physiology or Medicine.

The Nobel Prize in Chemistry is awarded annually by the Royal Swedish Academy of Sciences to scientists in the various fields of chemistry. It is one of the five Nobel Prizes established by the will of Alfred Nobel in 1895, awarded for outstanding contributions in chemistry, physics, literature, peace, and physiology or medicine. This award is administered by the Nobel Foundation and awarded by the Royal Swedish Academy of Sciences on proposal of the Nobel Committee for Chemistry, which consists of five members elected by the Academy. The award is presented in Stockholm at an annual ceremony on December 10th, the anniversary of Nobel's death.

November 7 is the 311th day of the year in the Gregorian calendar; 54 days remain until the end of the year.