Derek O'Brien (born 11 September 1957 in Dublin) was an Irish soccer player who played in the League of Ireland during the 1980s.
O'Brien was a right back who played for Boston United,Notts County Bohemians, Dundalk, Shamrock Rovers, Athlone Town, Longford Town and Home Farm F.C.. He represented Ireland at youth level and won a league winners medal with Dundalk. He made 28 league appearances for Bohs after signing from Boston United.
He signed for Rovers in the 1981 close season where he stayed for 2 seasons.
He is the brother of Fran O'Brienand Ray O'Brien (Shelboune FC, Man Utd and Notts County, Son of Fran O'Brien Senior, (Drumcondra FC) and father of Mark and Colin, who both play for Drogheda United.