The Baltimore Orioles hired O'Donnell in 1966, and he paired with Chuck Thompson to call their games on WJZ-TV (1966–1977), WBAL-AM (1966–1978), and WFBR-AM with fellow broadcaster Tom Marr from 1979 until health reasons forced him to step down early in the 1982 season.
O'Donnell also contributed to national coverage of the team's appearances in the 1969 World Series on NBC Television and the 1971 World Series on NBC Radio.
In addition to the Orioles, O'Donnell called Baltimore Colts radio from 1966 to 1968, as well as college football for ABC, regional MLB and NFL games for NBC, and college basketball for TVS Television Network.
O'Donnell died at age 56 of cancer at Johns Hopkins Hospital on October 29, 1982.
[3] He was posthumously given the Herb Armstrong Award by the Baltimore Orioles Hall of Fame in 2007.