Oskar Anton Bilharz was Mayor of Neutral Moresnet, a small neutral territory, from 7 February 1882 until 20 June 1885.
[1] Bilharz became mayor of Neutral Moresnet on 7 February 1882, succeeding Joseph Kohl to become the territory's fourth mayor.
As mayor, Bilharz served as the territory's head of state, alongside two commissioners, one each from the Kingdom of Prussia and Belgium.
During his term as mayor, in 1883, Neutral Moresnet switched its territorial flag to one with a tricolore with horizontal bars in black, white and blue.
[2] Bilharz was succeeded by Hubert Schmetz on 20 June 1885.