| Derek O'Brien | |
| Birth Date: | 1957 9, df=yes |
| Birth Place: | Dublin, Republic of Ireland |
| Position: | Right-back |
| Years1: | 1975–1976 |
| Clubs1: | Bohemians |
| Caps1: | 28 |
| Goals1: | ? |
| Years2: | 1976–1978 |
| Clubs2: | Dundalk |
| Caps2: | ? |
| Goals2: | 0 |
| Years3: | 1981–1983 |
| Caps3: | 24 |
| Goals3: | 2 |
| Years4: | 1985–1986 |
| Clubs4: | Athlone Town |
| Caps4: | 18 |
| Goals4: | 1 |
Derek O'Brien (born 11 September 1957 in Dublin) is a retired Irish footballer who played as a right-back in the League of Ireland during the 1980s.
O'Brien played for Bohemians, Dundalk, Shamrock Rovers, Athlone Town, Longford Town and Home Farm. He represented Ireland at youth level and made 28 league appearances for Bohs.
Derek played in all four European games during his time at Oriel Park, in ties against PSV Eindhoven and Hajduk Split.
He signed for Rovers in the 1981 close season where he stayed for two seasons.
He is the brother of Fran O'Brien and Ray O'Brien, son of Fran O'Brien Senior, (Drumcondra F.C.) and father of Mark and Colin.