The following information is taken from the Dictionary of the Older Scottish Tongue, available online at http://www.dsl.ac.uk/index.html. This is a work in progress.
| Spelling | Number | Dates & headers |
|---|---|---|
| Irwin | 4 | 1498 (bailȝery); 1570 (bruch); 1572-3 (borow-land); 1602 (court clerk) |
| Irving | 2 | 1572 (dam); 1644 (bailȝe) |
| Irwyn | 2 | 1324 (baxter); 1416 (burch) |
| Irewin | 1 | 1498 (chamerlanry) |
| Irvin | 1 | 1532 (borowmure) |