He played college football for the Purdue Boilermakers and was selected by the Raiders in the fourth round of the 2023 NFL draft.

O'Connell entered 2021 as the backup to Jack Plummer, but eventually took over as the starter and completed 315 of 440 passes for 3,712 yards with 28 touchdowns and 11 interceptions.

[15] On October 1, 2023, O'Connell made his first career NFL start, filling in for an injured Jimmy Garoppolo.

[20] Following a preseason quarterback competition with new free agent signing Gardner Minshew, O'Connell was named a backup to begin the season.

[22] In his first start of the season, O'Connell passed for 227 yards, one touchdown, and one interception as the Raiders lost to the Pittsburgh Steelers 32–13.

Against the Los Angeles Rams on October 20, O'Connell suffered a fractured thumb and was later placed on injured reserve.

[23] After missing four games, the Raiders activated O'Connell to the 53-man roster on November 28, ahead of the team's Week 13 matchup against the Chiefs.