| # | Name | Origin | Meaning | Gender | |
|---|---|---|---|---|---|
| 641 | Irene | Spanish | Peace. | F | |
| 642 | Irune | Spanish | Reference to the Holy Trinity. | F | |
| 643 | Isa | Spanish | Beautiful. Diminutive of Isabel: Devoted to God. A Spanish variant of Elizabeth. | F | |
| 644 | Isabel | Spanish | Devoted to God. A Spanish variant of Elizabeth. | F | |
| 645 | Isabela | Spanish | Variant of Elizabeth. My God is bountiful;God of plenty. | F | |
| 646 | Isabella | Spanish | My God is bountiful. God of plenty. Devoted to God. A Spanish variant of Elizabeth. | F | |
| 647 | Isabelle | Spanish | Variant of Isabel: Devoted to God. A Spanish variant of Elizabeth. | F | |
| 648 | Isadoro | Spanish | Strong gift. | M | |
| 649 | Isaias | Spanish | Salvation of Jehovah. | M | |
| 650 | Ishbel | Spanish | Variant of Isabel: Devoted to God. A Spanish variant of Elizabeth. | F | |
| 651 | Ishmael | Spanish | God listens. In the bible Ismael was son of Abraham by Sarah's Egyptian slave woman Hagar. | M | |
| 652 | Isidora | Spanish | Gifted with many ideas. | F | |
| 653 | Isidoro | Spanish | Gifted with many ideas. | M | |
| 654 | Isidro | Spanish | Gifted with many ideas. | M | |
| 655 | Isla | Spanish | Variant of Isabel: Devoted to God. A Spanish variant of Elizabeth. | F | |
| 656 | Ismael | Spanish | God listens. In the bible Ismael was son of Abraham by Sarah's Egyptian slave woman Hagar. | M | |
| 657 | Isobel | Spanish | Variant of Isabel: Devoted to God. A Spanish variant of Elizabeth. | F | |
| 658 | Itsaso | Spanish | Sea. | F | |
| 659 | Itxaro | Spanish | Hope. | F | |
| 660 | Ivan | Spanish | Archer. | M | |