Born in Königsberg, East Prussia, Germany (now Kaliningrad, Russia). After WW I service with the Prussian army, he worked for the Vienna and Berlin philhamonics and Max Reinhardt's theater. In 1925 he became assistant to the musical director of UFA, the German film company. He later became the company's musical director. In 1933 he came to the US, where he scored numerous Hollywood films: CARAVAN (1934), STOLEN HOLIDAY (1937), BLUEBEARD'S EIGHTH WIFE (1938), NINOTCHKA (1939), THE SHOP AROUND THE CORNER, ONE MILLION B.C. and PRIMROSE PATH (all 1940), TOPPER RETURNS, TANKS A MILLION and THAT UNCERTAIN FEELING (all 1941), TO BE OR NOT TO BE (1942), APPOINTMENT IN BERLIN and A NIGHT TO REMEMBER (both 1943), KNICKERBOCKER HOLIDAY, HAIL THE CONQUERING HERO and OUR HEARTS WERE YOUNG AND GAY (all 1944), IT'S IN THE BAG! and HOLD THAT BLONDE (both 1945), THE SIN OF HAROLD DIDDLEBOCK and LOST HONEYMOON (both 1947), LET'S LIVE A LITTLE and TELL IT TO THE JUDGE (both 1948), A KISS FOR CORLISS (1949), and A WOMAN OF DISTINCTION, THE PRETTY GIRL and EMERGENCY WEDDING (all 1950). Heymann returned to Germany in the early 1950s and continued to compose until 1960. He was a member of the jury at the Berlin International Film Festival in 1960. He died in Munich in 1961.

Nominated for Music Scoring Awards (Original Score) 1940: ONE MILLION B.C.  Nominated for Music Scoring Awards (Scoring of a Dramatic or Comedy Picture) 1941: TANKS A MILLION  Nominated for Music Scoring Awards (Scoring of a Dramatic or Comedy Picture) 1941: THAT UNCERTAIN FEELING  Nominated for Music Scoring Awards (Scoring of a Dramatic or Comedy Picture) 1942: TO BE OR NOT TO BE  Nominated for Music Scoring Awards (Scoring of a Musical Picture) 1944: KNICKERBOCKER HOLIDAY (w. Kurt Weill) 5 nominations