Boris Nikolaevich Delaunay or Delone (Russian: ????´? ??????´???? ??????´; March 15, 1890 – July 17, 1980) was one of the first Russian mountain climbers and a Soviet/Russian mathematician, and the father of physicist Nikolai Borisovich Delone.
The spelling Delone is a straightforward transliteration from Cyrillic he often used in later publications, while Delaunay is the French version he used in the early French and German publications.