| Code | Name | Region |
|---|---|---|
| DEOFN | Offingen | BY |
| DEOFQ | Offstein | RP |
| DEODG | Ofterdingen | BW |
| DEOFT | Ofterschwang | BY |
| DEOFM | Oftersheim | BW |
| DE77O | Ohlsbach | BW |
| DEOHJ | Ohlstadt | BY |
| DEOWL | Ohlweiler | RP |
| DE6MN | Ohmden | BW |
| DEOHG | Ohningen | BW |
| DEOHX | Ohorn | SN |
| DEODR | Ohrdruf | TH |
| DEOEH | Ohringen | BW |
| DEOBU | Olbernhau | SN |
| DEOLF | Olbersdorf | SN |
| DERDM | Odernheim | RP |
| DEOEF | Oebisfelde | ST |
| DEOED | Oederan | SN |
| DEOEM | Oedheim | BW |
| DEODI | Oeding | NW |
| DEOEL | Oelde | NW |
| DE67M | Oelixdorf | SH |
| DEOEA | Oelsa/freital | SN |
| DEOSZ | Oelsnitz | SN |
| DEOSV | Oelsnitz/vogtland | SN |
| DEOER | Oer-erkenschwick | NW |
| DEOOL | Oerlenbach | BY |
| DEOEN | Oerlinghausen | NW |
| DE59N | Oersdorf | SH |
| DE68E | Oesterdeichstrich | SH |
| DEOSW | Oestrich-winkel | HE |
| DEOTI | Oettingen In Bayern | BY |
| DEOZN | Oetzen | NI |
| DEONA | Offenau | BW |
| DEOFF | Offenbach | HE |
| DEXYC | Oberwiesenthal | SN |
| DEOWT | Oberwinter | RP |
| DEOBH | Oberwolfach | BW |
| DEZ3B | Oberzent | HE |
| DEOZ9 | Oberzissen | RP |
| DEOHU | Obhausen | ST |
| DEOBX | Obing | BY |
| DEOGH | Obrigheim | BW |
| DEOHM | Obrigheim | RP |
| DEOC2 | Ocholt | NI |
| DEOCF | Ochsenfurt | BY |
| DEOCH | Ochsenhausen | BW |
| DEOCD | Ochtendung | RP |
| DEOCT | Ochtrup | NW |
| DEOCK | Ockenheim | RP |