- Jan 3 Musa Kaleem [Orlando Wright], American jazz saxophonist, born in Wheeling, West Virginia (d. 1988)
- Jan 7 John Lanigan, Australian operatic tenor (Covent Garden), born in Seddon, Victoria (d. 1996)
- Jan 9 Seymour Barab, American cellist (Philip Glass Ensemble), and composer of fairy tale operas (Little Red Riding Hood), born in Chicago, Illinois (d. 2014)
- Jan 12 Leo Smit, Dutch composer, born in Philadelphia, Pennsylvania (d. 1943)
- Jan 14 Mark Lawrence, American pianist (Alice Pearce), born in Washington, D.C.
- Jan 20 Connie Haines [Yvonne Jasme], American big-band vocalist (Harry James; Tommy Dorsey), born in Savannah, Georgia, (d. 2008)
- Jan 21 Todor Popov, Bulgarian composer, born in Dryanovo (d. 2000)
- Jan 22 Andre Hodeir, composer
- Jan 25 Alfred Reed, American composer, born in NYC, New York (d. 2005)
- Jan 26 Frantisek Chaun, composer
- Jan 26 Johannes Driessler, composer
- Jan 30 Bernie Leighton, American orchestra leader (Chance of a Lifetime), born in West Haven, Connecticut (d. 1994)
- Jan 31 Carol Channing, American actress (Gentlemen Prefer Blondes, Hello Dolly), singer and comedian, born in Seattle, Washington (d. 2019)
- Jan 31 Mario Lanza [Alfredo Arnold Cocozza], Italian-American actor and singer (Great Caruso, Toast of New Orleans), born in Philadelphia, Pennsylvania (d. 1959)
About January 1921
How Old? 99 or 100 years old
Generation: Greatest Generation
Leap Year: No