| Ian | Ialano | Iano | Ibero | Ibitz |
| Ibitzo | Ibn | Ibo | Ibor | |
| Ibro | Ibrizo | Icabido | Icaras | Icarus |
| Icco | Ice | Iceman | Ice-T | Ichy |
| Ico | Icon | Icor | Icore | Icos |
| Icost | Icy | Idax | Idea | Ideal |
| Idefix | Idle | Ido | Idol | Idor |
| Idorus | Idu | Idun | Idus | Idux |
| Iffland | Iffo | Iggy | Igloo | Iglu |
| Ignatius | Ignaz | Igor | Igoron | Ihno |
| Ikarus | Iko | Ikus | Ildo | Ilex |
| Ilg | Ilgor | Ilio | Iljosch | Iljoscha |
| Ilkas | Ilko | Ilkus | Illan | Illias |
| Illmar | Illos | Illoso | Illus |
Ilma |
| Jaap | Jabberwocky | Jack | Jack Daniels | Jacko |
| Jackpot | Jacks | Jackson | Jacky | Jäcky |
| Jacob | Jaffa | Jag | Jagger | Jago |
| Jagos | Jaime | Jairon | Jake | Jako |
| Jakob | Jalapeno | Jalk | Jalon | Jam |
| Jago | Jakoda | Jacomo | ||
| Jambo | James | Jamie | Jamiro | |
| Jamiron | Jamiros | Jamirosch | Jamy | Jan |
| Jando | Janek | Jango | Jangos | Janis |
| Janko | Jannick | Jannis | Janno | Janos |
| Janosch | Janti | Janus | Jap | Jaques |
| Jargo | Jari | Jaro | Jarod | Jaron |
| Jaros | Jarosch | Jascha | Jasey | Jasko |
| Jason | Jaster | Jasper | Jasso | Jassop |
| Jatao | Jatoo | Jausi | Java | Jax |
| Jay | Jazek | Jazz | Jazzman | Jean |
| Jakiro | Jakito | |||
| Jed | Jeff | Jefferson | ||
| Jeffrey | Jekyll | Jemo | Jemos | Jenk |
| Jenkes | Jenky | Jeno | Jenos | Jenoso |
| Jeremias | Jeremy | Jeri | Jerk | Jerky |
| Jero | Jerros | Jerome | Jeron | Jerrit |
| Jerrom | Jerron | Jerry | Jerry-Lee | Jervis |
| Jever | Jehle | JERRYJESS | Jessy | |
| Jesko | Jesper | Jesse James | Jessiko | Jester |
| Jet | Jethro | Jigsaw | Jim | |
| Jimbo | Jimmy | Jingles | Jingo | |
| Jinko | Jinno | Jirko | Jitterbug | JJ (JeyJey) |
| Jo | Jock | Jockel | Jodo | Joe |
| Joel | Joey | Jogi | Jo-han | Johann |
| John | John Boy | Johnny | Johnnyboy | |
| Johns | Johnson | Johnto | Jojo | Joke |
| Joker | Jokey | Jokim | Joko | Jokos |
| Jolandi | Jomas | Jonas | Jonathan | Jones |
| Jonny | Joon | Joop | Joost | Jordan |
| Joringel | Jorso | Jorus | Josch | Joscha |
| Joschi | Joschka | Joscho | Josef | Joshua |
| Josias | Josip | Josse | Jovan | Jucan |
| JoJo | Joshie | |||
| Judo | Jukas | Juki | Jukie | Julep |
| Julepp | Julian | Julien | Julio | Julius |
| Jumbo | Jump | Jumper | Jumpy | Junge |
| Junior | Junios | Juniper | Junkos | Juno |
| Jupiter | Jupp | Jurek | Juri | Jurix |
| Juro | Just | Justin | Justus | Juwel |
| Jux | Jocker |