| into power | | | |
| into the wide blue yonder | | | |
| into thin air | | | |
| in touch | | | |
| in two jumps | | | |
| in two shakes | | | |
| in two shakes of a lamb's tail | | | |
| in vain | | | |
| in view of | | | |
| in virtue of | | | |
| invited to the cookout | | | |
| in wine | | | |
| in with a chance | | | |
| in words of one syllable | | | |
| in your dreams | | | |
| in your face | | | |
| I rest my case | | | |
| iron eagle | | | |
| iron fist | | | |
| ironing board | | | |
| irons in the fire | | | |
| is a bear Catholic | | | |
| I see, said the blind man | | | |
| I take it | | | |
| it can't be helped | | | |
| itch the ditch | | | |
| itchy feet | | | |
| itchy trigger finger | | | |
| I tell a lie | | | |
| I tell you | | | |
| it figures | | | |
| it is what it is | | | |
| it's about time | | | |
| it's all good | | | |
| it's all Greek to me | | | |
| it's early days | | | |
| it's five o'clock somewhere | | | |
| it's none of your business | | | |
| it takes all kinds to make a world | | | |
| it takes one to know one | | | |
| it takes two to make a quarrel | | | |
| it takes two to tango | | | |
| ivory-pounder | | | |
| ivory-thumper | | | |
| ivory tickler | | | |
| ivory tower | | | |
| I wish | | | |
| I would | | | |