| Iachima | From Shakespeare's play Merry Wives of Windsor. | |
| Iagan | Scottish | The little fiery one. |
| Iago | Spanish | Spanish form of James. The supplanter. Also from Shakespeare's play Othello. |
| Iain | Gaelic | God's gracious gift |
| Ian | Hebrew | God is gracious. The Scottish form of John. |
| Ibeamaka | African | the agnates are splendid |
| Ibrahim | Hebrew | The father of many. |
| Icarus | Greek | A legendary figure. |
| Ichabod | Hebrew | The glory has departed. |
| Iden | Old English | Prosperous. |
| Idris | Arabic/Welsh | Arabic: A good man. Welsh: A fiery, impulsive lord. |
| Idwal | Welsh | The lord of the wall or rampart. |
| Iestin | Welsh | Welsh form of Justin. Just or true. |
| Iestyn | Welsh | Welsh form of Justin. Just or true. |
| Ieuan | Welsh | Welsh form of John. God is gracious. Also see Evan and Owen. |
| Ifor | Welsh | A traditional name of uncertain meaning. |
| Ignacio | Latin | one who is lively |
| Ignatius | Latin | Ardent, fiery. |
| Igor | Scandinavian | Hero. Also a Russian variation of the name George. |
| Ihorangi | Polynesian | Rain. |
| Ike | Hebrew | Laughter, the laughing one. |
| Ikey | Hebrew | Laughter, the laughing one. |
| Ilar | Welsh | Cheerful. |
| Ilario | Italian | Cheerful. |
| Ilhan | Turkish | |
| Ilias | Latin | Jehovah is my God |
| Ilie | Romanian | Romanian form of Elias. The Lord is God. |
| Ilya | Russian | Russian form of Elijah. The Lord is God. |
| Imam | Arabic | One who believes in God. A boy or girl's name. |
| Immanuel | German | God is with us. |
| Imre | Hungarian | An industrious ruler. |
| Ince | Latin | innocent |
| Indra | Sanskrit | The God of the atmosphere and sky. |
| Ingemar | Old Norse | A famous son. |
| Inger | Old Norse | A son's army or a Hero's daughter. A boy or girl's name. |
| Inglebert | Teutonic | A bright Angel. |
| Ingmar | Scandinavian | famous son |
| Ingo | ||
| Ingolf | ||
| Ingram | Teutonic | The raven. |
| Inigo | Latin | Ardent, fiery. |
| Innes | Celtic/Gaelic | An island in the river, or from the island. Also see Ennis. |
| Innocent | Latin | Harmless, innocent. The name of several saints and popes. |
| Ioannes | Greek | Greek form of John. |
| Iolo | Welsh | A handsome lord. |
| Iolyn | Welsh | A handsome lord. |
| Ion | Romanian | Romanian form of John. God is gracious. |
| Iorweth | Welsh | A handsome lord. |
| Ira | Hebrew | Watchful, vigilant. A biblical name. |
| Iravan | Hindu | son of Arjuna/Uloopi |
| Irawaru | Polynesian | A figure from legend. |
| Irvin | Anglo-Saxon | lover of the sea |
| Irving | Scottish | Handsome and fair. |
| Irwin | Old English | From the words `boar' and 'friend'. |
| Isa | Sanskrit/Teutonic | Sanskrit: A lord. Teutonic: Strong-willed. A boy or girl's name. |
| Isaac | Hebrew | Laughter, the laughing one. The son of Abraham in the Bible. |
| Isaiah | Hebrew | God is salvation, or God is my helper. One of the prophets in the Bible. Lived in the 8th century BC. |
| Isha | Hindu | one who protects |
| Ishmael | Hebrew | The Lord will hear. The first son of Abraham in the Bible. |
| Ishver | Hindu | |
| Isidore | Greek | The gift of Isis (an Egyptian goddess). |
| Isidro | Spanish | Chidro |
| Israel | Hebrew | The Lord's soldier. |
| Istvan | Hungarian | Hungarian form of Stephen. A crown or garland. |
| Itzaak | Hebrew | Laughter, the laughing one. |
| Itzak | Hebrew | laughter |
| Itziamar | ||
| Itzik | Hebrew | Laughter, the laughing one. |
| Ivan | Eastern European form of John. | |
| Ivar | Old Norse | A battle archer. |
| Ives | Old English | The little archer. |
| Ivo | German | The little archer. |
| Ivor | Old Norse | A battle archer. |
| Izaak | Dutch | Laughter, the laughing one. |