Simeon worked regularly with King Oliver in 1927, and with his successor Luis Russell the following year. After returning to Chicago, he was with Erskine Tate's Vendome Orchestra (1928-1930); and then joined Earl Hines' big band in 1931, where during the next six years he was well featured on both clarinet and tenor, making many recordings with the great pianist. After leaving Hines, Simeon spent briefer periods in the big bands of Horace Henderson (1938), Walter Fuller (1940), and Coleman Hawkins. He was a member of the Jimmie Lunceford Orchestra from 1942 on, not only staying during the big band's declining years but remaining after Lunceford's death in 1947 during the three years that Ed Wilcox led the ghost orchestra. Simeon also recorded Dixieland with Kid Ory during 1944-1945. Moving back to New York, Omer Simeon became the clarinetist with Wilbur DeParis' "New New Orleans Jazz Band," touring and recording with the spirited ensemble up until his death in 1959. Although a highly rated clarinetist for 35 years and considered one of the most technically skilled of all New Orleans-born reed players, Omer Simeon's only opportunities to lead record sessions resulted in just two songs in 1929, and a Jazztone trio set in 1954.