- Sep 12 Walther Amelung, German archaeologist, dies at 61
- Sep 12 Sarah Frances Whiting, American physicist and astronomer, dies at 80
Isadora Duncan
Sep 14 Isadora Duncan, American free form/interpretative dancer, dies at 50 due to her scarf becoming entangled in her car's wheel

Isadora Duncan
- Sep 15 Herman Gorter, Dutch socialist and poet (May, Tiny Hero's Poem), dies at 62
- Sep 19 Michael Peter Ancher, Danish painter (b. 1849)
- Sep 20 George Nichols, American director and actor (His Favorite Pastime, Star Boarder), dies at 62 or 63
- Sep 22 Giannotto Bastianelli, Italian musician and composer, dies at 44
- Sep 29 Willem Einthoven, Dutch physiologist and inventor of the electrocardiodiogram (Nobel Prize in Medicine 1924), dies at 67
- Sep 29 Arthur Achleitner, German writer, dies at 69