O'Connor made his debut first-class appearance for Derbyshire in the 1900 season in May against Lancashire when he took 5 wickets in both innings at 5–56 and 5–69.
O'Connor was a right-arm off-break and medium-pace bowler and took 24 first-class wickets at an average of 15.79 and a best performance of 5 for 56.
He was a right-handed tail end batsman and played 14 innings in 9 first-class matches with a top score of 17 and an average of 6.11.
He played another minor county season for Cambridgeshire in 1912 and started umpiring first-class matches for Cambridge University again.
His son Jack O'Connor was born at Cambridge in 1897 and played cricket for England and Essex.