| Impact - The instant the ball hits the club. |
| In - The later nine holes of an eighteen hole golf course. |
| Inland - in play - Inside the golf course as apposed to out of bounds. |
| Inside - Where a golfer is closer to the hole than their challenger's ball. |
| Intended line - This is the line a golfer anticipates their ball to go after it has been hit. |
| Interlocking grip - This is a type of grip where a golfer links his/her little finger of the left hand with the index finger of the right hand. The opposite applies to a left-handed golfer. |
| Iron - A golf club with an iron or steel head. |