- Ioane #47,521
- Ioannides #105,079
- Ioannidis #70,833
- Ioannou #41,657
- Iobst #105,600
- Iocca #109,758
- Iocco #62,903
- Iodice #39,052
- Ioerger #114,424
- Ioffe #52,736
- Ioli #113,791
- Ion #37,029
- Iona #94,311
- Ionadi #160,975
- Ionescu #28,065
- Iongi #116,829
- Ionita #91,221
- Ionno #157,234
- Ionta #126,018
- Ioppolo #120,187
- Iordanov #142,108
- Iorfida #146,201
- Iorg #99,845
- Iorga #135,593
- Iori #110,286
- Iorillo #133,863
- Iorio #13,944
- Iorizzo #127,494
- Iosefa #104,602
- Iosia #143,149
- Iossi #150,452
- Iosua #108,734
- Iosue #78,040
- Iott #41,657
- Iovanna #116,829
- Iovieno #159,712
- Iovine #46,404
- Iovinelli #97,210
- Iovino #20,421
- Iozzi #113,791
- Iozzia #122,314
- Iozzo #59,901