Denmark: Fixed and Moveable Feast Days beginning with O
A
| B
| C
| D
| E
| F
| G
| H
| I
| J
| K
| L
| M
| N
| O
| P
| Q
| R
| S
| T
| U
| V and W
| X, Y, and Z
| Octavianus | 22 March | |
| Oculi | see Oculi | |
| Odalricus | 4 July | |
| Oderus | 9 November | |
| Odilo | 1 January | |
| Olafsmessa fyrri | 29 July | |
| Olat | 16 December | |
| Olivarum dies | see Palmarum | |
| Oliverus | 20 August | |
| Øllegaard | 28 February | |
| Olsdag | 29 July | |
| Oluf | 29 July | |
| Olympia | 15 April | |
| Olympiades & Maxim. | 17 December | |
| Olympiades vic. | 17 December | |
| Omnium Fidelium commemoratio | 2 November | |
| Omnium Sanctorum | 1 November | |
| Onesimus | 16 February | |
| Onesiphorus | 21 March | |
| Onuphrius | 10 June | |
| Optatus | 4 June | |
| Orestes | 13 December | |
| Osapientia | 16 December | |
| Ositha | 7 October | |
| Osmundus | 4 December | |
| Oster Sonntag | see Påske (Easter) | |
| Osvaldus rex | 5 August | |
| Othenius | 16 November | |
| Othilla | 13 December | |
| Othmarus | 16 November | |
| Otho | 2 July | |
| Otho in Sweden | 9 April | |
| Otto in Denmark | 4 November |