- 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, American classical pianist, composer (The Alchemy of Love), teacher and photographer, born in Philadelphia, Pennsylvania (d. 1999)
- Jan 14 Lucy Reed [Dollinger], American jazz vocalist (Woody Herman; Charlie Ventura), born in Marshfield, Wisconsin (d. 1998)
- Jan 14 Mark Lawrence, American pianist (Alice Pearce), and songwriter, and theatrical producer, born in Washington, D.C. (d. 1991)
- Jan 18 Ray Sims, American jazz trombonist (Benny Goodman; Les Brown; Harry James; Red Norvo; Zoot Sims), born in Wichita, Kansas (d. 2000)
- Jan 20 Connie Haines [Yvonne Jasme], American pop and big-band singer (Harry James; Abbott and Costello Show; Tommy Dorsey), born in Savannah, Georgia (d. 2008) [1]
- Jan 21 Todor Popov, Bulgarian composer, born in Dryanovo, Bulgaria (d. 2000)
- Jan 22 André Hodeir, French classical and jazz violinist, and composer, born in Paris (d. 2011)
- Jan 25 Alfred Reed, American composer, born in New York City (d. 2005)
- Jan 26 Frantisek Chaun, Czech composer, born in Kaplice, Bohemia, Austrian Empire (now Czechia) (d. 1981)
- Jan 26 Johannes Driessler, German organist and composer, born in Friedrichsthal, Germany (d. 1988)
- 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? 103 years old
Generation: Greatest Generation
Leap Year: No