He was signed by the Baltimore Orioles as an amateur free agent in 1954, and was a bonus baby, never spending a day in the minors.

Included in the nine were future hall of fame players Willie Mays, Stan Musial, Hank Aaron, Ernie Banks and Bill Mazeroski.

On May 19, 1959, O'Dell hit a 120-foot inside-the-park home run for the Orioles in a 2–1 victory over the Chicago White Sox.

[5] On November 30, 1959, the Orioles traded him, along with Billy Loes, to the San Francisco Giants for Jackie Brandt, Gordon Jones and Roger McCardell.

[2][13] During his time with the Orioles, O'Dell's roommate was future hall of fame third baseman Brooks Robinson.

O'Dell allowed just one run and two hits in nine innings and struck out a career high 13 batters in a relief role, recording the win.

[14] In 1962, O'Dell won a career high 19 games for the NL champion Giants.

[8][2] O'Dell was the losing pitcher in Game 1 of the 1962 World Series against the New York Yankees.

He gave up a two-run double to Roger Maris, an RBI single to Tony Kubek, a solo home run to Clete Boyer, and finally an RBI single to Dale Long before being relieved by manager Alvin Dark for veteran pitcher Don Larsen, thus allowing five earned runs in 71⁄3 innings.

[2] On July 23, 1964, O'Dell allowed 12 runs (11 earned) in seven innings in a 13–4 loss to the Cubs.

While O'Dell's ERA was lower after that game, he only made one further start, working mainly out of the bullpen for the rest of the year.

[6] He died at a hospital in Newberry, South Carolina on September 12, 2018, from complications of Parkinson's disease, aged 85.