| Akta X |
 Czechoslovakia |
| Akte X |
 West Germany |
| Akte X - Die unheimlichen Fälle des FBI |
 Austria |
| Akte X: Die unheimlichen Fälle des FBI |
West Germany |
| Akty X |
 Slovakia |
| Los archivos Secretos X |
 Chile |
| Arkiv X |
 Sweden |
| Arquivo X |
 Brazil |
| Aux frontières du réel |
 Canada |
| Aux frontières du réel (first season title) |
 France |
| Código X |
 Argentina |
| Dosarele X |
 Romania |
| Dosijei Iks |
 Bosnia |
| Dosjei X |
 Croatia |
| Dosjeji X |
 Slovenia |
| Expediente X |
 Spain |
| Los expedientes secretos X |
Argentina |
| Los expedientes secretos X |
 Ecuador |
| Los expedientes secretos X |
 Mexico |
| Los expedientes secretos X |
 Peru |
| Los expedientes Secretos X |
Chile |
| Los expedientes Secretos X (complete title) |
 Venezuela |
| Ficheiros Secretos |
 Portugal |
| Files in the Dark (literal English title) |
 Israel |
| Gizli Dosyalar |
 Turkey |
| Hồ Sơ Tuyệt Mật |
 Vietnam |
| Salaiset kansiot |
 Finland |
| Salaiset kansiot: Biogenesis (video box title) |
Finland |
| Salaiset kansiot: Closure (video box title) |
Finland |
| Salaiset kansiot: Kansio 2 - Tooms (video box title) |
Finland |
| Salaiset kansiot: Kansio 5 - 82517 (video box title) |
Finland |
| Salaiset kansiot: The End (video box title) |
Finland |
| Salatoimikud |
 Estonia |
| Sirli fayllar |
 Uzbekistan |
| Strengt fortroligt |
 Denmark |
| Untitled X Files Reboot |
|
| Untitled X-Files Revival |
|
| X failai |
 Lithuania |
| The X Files |
 India |
| The X Files |
India |
| The X Files |
 South Korea |
| The X Files |
 Netherlands |
| The X Files |
 Singapore |
| The X Files |
 Thailand |
| The X Files (trailer title) |
 USA |
| The X Files |
 South Africa |
| The X Files |
 United Arab Emirates |
| The X Files |
 Australia |
| The X Files |
Canada |
| The X Files |
 Egypt |
| The X Files |
 United Kingdom |
| The X Files |
 Greece |
| The X Files |
 Hong Kong |
| The X Files |
 Indonesia |
| X-akták |
 Hungary |
| X-faili. Slepenās lietas |
 Latvia |
| X-Fairu |
 Japan |
| X-File |
Japan |
| X-Files (tenth season title) |
France |
| X-Files |
 Italy |
| The X-Files - Salaiset kansiot |
Finland |
| X-Files : Aux frontières du réel |
France |
| The X-Files : Aux frontières du réel (second season title) |
France |
| The X-Files (complete title) |
 Philippines |
| The X-Files |
USA |
| Xファイル |
Japan |
| X檔案 |
 Taiwan |
| Z archiwum X |
 Poland |
| Досије икс |
 Serbia |
| Досиетата X |
 Bulgaria |
| Секретні матеріали |
 Ukraine |
| Секретные материалы |
 Russia |
| Цілком таємно |
Ukraine |
