| Hànyǔ | cmn-003 |
| shíèryuè | |
| Afrikaans | afr-000 | Desember |
| Classical Arabic—ASJP | arb-001 | kānūn alʾāwa'al |
| asturianu | ast-000 | avientu |
| azərbaycanca | azj-000 | dekabr |
| biełaruskaja łacinka | bel-002 | snežan' |
| bosanski | bos-000 | decembar |
| brezhoneg | bre-000 | Kerzu |
| bălgarski ezik | bul-001 | dekemwri |
| català | cat-000 | desembre |
| čeština | ces-000 | prosinec |
| Noxçiyn mott | che-002 | Ġuran-butt |
| Çăvaşla | chv-001 | raschtaw |
| 普通话 | cmn-000 | 十二月 |
| 國語 | cmn-001 | 十二月 |
| kaszëbsczi jãzëk | csb-000 | gòdnik |
| Cymraeg | cym-000 | Rhagfyr |
| dansk | dan-000 | december |
| Deutsch | deu-000 | Dezember |
| dolnoserbska reč | dsb-000 | december |
| dolnoserbska reč | dsb-000 | zymski |
| eesti | ekk-000 | detsember |
| Ellinika | ell-003 | Dekémvrios |
| Ellinika | ell-003 | Dekémvris |
| English | eng-000 | December |
| Esperanto | epo-000 | decembro |
| euskara | eus-000 | abendu |
| føroyskt | fao-000 | desember |
| suomi | fin-000 | joulukuu |
| français | fra-000 | décembre |
| Frysk | fry-000 | desimber |
| Gàidhlig | gla-000 | Nollaig |
| Gaeilge | gle-000 | Nollaig |
| galego | glg-000 | decembro |
| avañeʼẽ | gug-000 | jasypakõi |
| Gujrātī | guj-001 | ḍisembar |
| ISO 259-3 | heb-001 | detzémber |
| hrvatski | hrv-000 | prosinac |
| hornjoserbšćina | hsb-000 | december |
| hornjoserbšćina | hsb-000 | hodownik |
| magyar | hun-000 | december |
| interlingua | ina-000 | decembre |
| bahasa Indonesia | ind-000 | Desember |
| íslenska | isl-000 | desember |
| italiano | ita-000 | dicembre |
| 日本語 | jpn-000 | じゅうにがつ, jūnigatsu |
| Kartuli | kat-001 | dek'emberi |
| Mongol khel | khk-001 | arwan chojordugaar sar |
| Kurmancî | kmr-000 | çilêya pêşîn |
| Hangungmal | kor-001 | sibiwol |
| Ladino | lad-001 | dezëmber |
| latine | lat-000 | December |
| Limburgs | lim-000 | desember |
| lingála | lin-000 | desembere |
| lietuvių | lit-000 | gruodis |
| MaraaThii | mar-001 | ḍisembar |
| ɔl Maa | mas-000 | olapa le tomon oo are |
| mokshenj kalj | mdf-001 | dekabarjkov |
| teny malagasy | mlg-000 | desambra |
| Malti | mlt-000 | Dicembru |
| reo Māori | mri-000 | Hakihea |
| reo Māori | mri-000 | Tīhema |
| Nederlands | nld-000 | december |
| bokmål | nob-000 | desember |
| Novial | nov-000 | desembre |
| occitan | oci-000 | decembre |
| Panjābī | pan-001 | dasambar |
| Isfahani | pes-001 | Desâmbr |
| polski | pol-000 | grudzień |
| português | por-000 | dezembro |
| Qusqu qhichwa simi | quz-000 | raymikis |
| lingua rumantscha | roh-000 | december |
| română | ron-000 | decembrie |
| русский | rus-000 | декабрь |
| russkij | rus-001 | dekabr' |
| slovenčina | slk-000 | december |
| slovenščina | slv-000 | decémber |
| davvisámegiella | sme-000 | juovlamánnu |
| gagana faʻa Samoa | smo-000 | Tesema |
| chiShona | sna-000 | Zvita |
| Sesotho | sot-000 | Tshitwe |
| español | spa-000 | diciembre |
| shqip | sqi-000 | dhjetor |
| srpski | srp-001 | decembar |
| svenska | swe-000 | december |
| Kiswahili | swh-000 | desemba |
| Tagalog | tgl-000 | Disyembre |
| phasa thai | tha-001 | than waa khom |
| türkmençe | tuk-000 | dekabr |
| Türkçe | tur-000 | aralık |
| Latynytsia | ukr-001 | gruden' |
| Volapük | vol-000 | Dekul |
| lingaedje walon | wln-000 | décimbe |
| yidish | ydd-001 | detsember |
| Bahasa Malaysia | zsm-000 | Disember |