| 8941 | January 21 | Birth | 1867 – Ludwig Thoma, German paramedic and author (d. 1921) |
| 8942 | January 21 | Birth | 1867 – Maxime Weygand, Belgian-French general (d. 1965) |
| 8943 | January 21 | Birth | 1878 – Vahan Tekeyan, Armenian poet and activist (d. 1948) |
| 8944 | January 21 | Birth | 1879 – Joseph Roffo, French rugby player and tug of war competitor (d. 1933) |
| 8945 | January 21 | Birth | 1881 – Ernst Fast, Swedish runner (d. 1959) |
| 8946 | January 21 | Birth | 1882 – Pavel Florensky, Russian mathematician and theologian (d. 1937) |
| 8947 | January 21 | Birth | 1882 – Francis Gailey, Australian-American swimmer (d. 1972) |
| 8948 | January 21 | Birth | 1883 – Olav Aukrust, Norwegian poet and educator (d. 1929) |
| 8949 | January 21 | Birth | 1883 – Eulogio Rodriguez, Filipino politician, 7th President of the Senate of the Philippines (d. 1964) |
| 8950 | January 21 | Birth | 1884 – Roger Nash Baldwin, American author and activist, co-founded the American Civil Liberties Union (d. 1981) |
| 8951 | January 21 | Birth | 1885 – Ernst Gustav Kühnert, Estonian-German architect and historian (d. 1961) |
| 8952 | January 21 | Birth | 1885 – André Lagache, French racing driver (d. 1938) |
| 8953 | January 21 | Birth | 1885 – Umberto Nobile, Italian engineer and explorer (d. 1978) |
| 8954 | January 21 | Birth | 1887 – Maude Farris-Luse, American super-centenarian (d. 2002) |
| 8955 | January 21 | Birth | 1887 – Georges Vézina, Canadian ice hockey player (d. 1926) |
| 8956 | January 21 | Birth | 1895 – Cristóbal Balenciaga, Spanish fashion designer, founded Balenciaga (d. 1972) |
| 8957 | January 21 | Birth | 1897 – René Iché, French sculptor (d. 1954) |
| 8958 | January 21 | Birth | 1898 – Avery Claflin, American banker and composer (d. 1979) |
| 8959 | January 21 | Birth | 1899 – Alexander Tcherepnin, Russian-American pianist and composer (d. 1977) |
| 8960 | January 21 | Birth | 1901 – Ricardo Zamora, Spanish footballer and manager (d. 1978) |
| 8961 | January 21 | Birth | 1904 – Puck van Heel, Dutch footballer (d. 1984) |
| 8962 | January 21 | Birth | 1905 – Christian Dior, French fashion designer, founded Christian Dior S.A. (d. 1957) |
| 8963 | January 21 | Birth | 1905 – Karl Wallenda, German-American acrobat and tightrope walker, founded The Flying Wallendas (d. 1978) |
| 8964 | January 21 | Birth | 1906 – Igor Moiseyev, Russian dancer and choreographer (d. 2007) |
| 8965 | January 21 | Birth | 1909 – Todor Skalovski, Macedonian composer and conductor (d. 2004) |
| 8966 | January 21 | Birth | 1910 – Albert Rosellini, American lawyer and politician, 15th Governor of Washington (d. 2011) |
| 8967 | January 21 | Birth | 1910 – Eua Sunthornsanan, Thai composer and bandleader (d. 1981) |
| 8968 | January 21 | Birth | 1911 – Bill Graber, American pole vaulter (d. 1996) |
| 8969 | January 21 | Birth | 1912 – Konrad Emil Bloch, German-American biochemist and academic, Nobel Prize laureate (d. 2000) |
| 8970 | January 21 | Birth | 1913 – William Ungar, Polish-American author and philanthropist, founded the National Envelope Corporation (d. 2013) |