Daniel Cornelius O'Connor (August 11, 1868 – March 3, 1942) was a Canadian Major League Baseball first baseman who played for the Louisville Colonels of the American Association in 1890.

O'Connor played in 6 games for the Colonels, who won the 1890 AA pennant with a record of 88–44.

At first base he handled 58 chances without an error and participated in 3 double plays.

O'Connor died in his hometown of Guelph, Ontario, Canada at the age of 73.

This biographical article relating to a Canadian baseball first baseman is a stub.