Oldenburg (Oldenburg)

Oldisleben (Saxe-Weimar-Eisenach)

Olpe (Westphalia)

Oppenau (Baden)

Ostrand (Saxony)

Oschersleben (Saxony)

Osterburg (Saxony)

Osterode (East Prussia)

Ostrowo (Posen)

Ottmachau (Silesia)