| Otto Hamacek | |
| Fullname: | Otto Hamacek |
| Birth Date: | 1 October 1896 |
| Birth Place: | Vienna, Austro-Hungary |
| Position: | Midfielder |
| Years1: | 1919–1924 |
| Caps1: | 1 |
| Goals1: | 0 |
| Manageryears1: | 1929 |
| Managerclubs1: | Luzern |
| Manageryears2: | 1931–1932 |
| Managerclubs2: | Vojvodina |
Otto Hamacek (1 October 1896 – 26 March 1984) was an Austrian football player and coach.
As player he was a midfielder and played with SK Rapid Wien in the 1923–24 Austrian championship.[1] He played for the Vienna selection team in 1919 representing Rapid.[2]
Later he became a coach and managed Swiss top-flight side FC Luzern between February and summer 1929[3] and Yugoslav side FK Vojvodina in the season 1931–32.[4]