| # | Name | Origin | Meaning | Gender | |
|---|---|---|---|---|---|
| 1101 | Ierne | Irish | From Ireland. | F | |
| 1102 | Ighneachan | Irish | Variant of Eigneachan: Strong man. | M | |
| 1103 | Ilane | Irish | Island. | F | |
| 1104 | Imogen | Irish | Daughter. Last born. | F | |
| 1105 | Inerney | Irish | Steward of church lands. | M | |
| 1106 | Inis | Irish | From Ennis. | F | |
| 1107 | Inis | Irish | From the river island. | M | |
| 1108 | Iniss | Irish | From the river island. | M | |
| 1109 | Innes | Irish | From the river island. | M | |
| 1110 | Innis | Irish | From the river island. | M | |
| 1111 | Inys | Irish | From the river island. | M | |
| 1112 | Isibeal | Irish | Irish form of Isabel: consecrated to God. | F | |
| 1113 | Isleen | Irish | Vision. | F | |
| 1114 | Islene | Irish | Vision. | F | |
| 1115 | Ita | Irish | Thirst. Thirsty. | F | |
| 1116 | Izett | Irish | Irish form of Isolda. | F | |
| 1117 | Jana | Irish | Feminine form of John: God is gracious. | F | |
| 1118 | Jarlath | Irish | Tributary lord. | M | |
| 1119 | Juno | Irish | Variant of Una: Lamb; together. | F | |
| 1120 | Justin | Irish | Judicous. | M | |