| # | Name | Origin | Meaning | Gender | |
|---|---|---|---|---|---|
| 1541 | Reidhachadh | Irish | From the smooth field. | M | |
| 1542 | Reilley | Irish | Rye. Form of Ryley. | M | |
| 1543 | Reilly | Irish | Surname. Rye. Form of Ryley. | M | |
| 1544 | Renny | Irish | Wealthy or charming. | F | |
| 1545 | Renny | Irish | Mighty. | M | |
| 1546 | Reynolds | Irish | Surname. | M | |
| 1547 | Riagan | Irish | Little king. | M | |
| 1548 | Rian | Irish | Kingly. | M | |
| 1549 | Richael | Irish | Name of a saint. | F | |
| 1550 | Riddoc | Irish | From the smooth field. | M | |
| 1551 | Riddock | Irish | From the smooth field. | M | |
| 1552 | Riley | Irish | Rye. Form of Ryley. Surname. | M | |
| 1553 | Riobard | Irish | Royal bard. | M | |
| 1554 | Rioghnach | Irish | Royal. | F | |
| 1555 | Rion | Irish | Kingly. | M | |
| 1556 | Riona | Irish | Royal. | F | |
| 1557 | Riordain | Irish | Bright. | M | |
| 1558 | Riordan | Irish | Bright. | M | |
| 1559 | Roane | Irish | Red-haired; red. | M | |
| 1560 | Roark | Irish | Famous ruler. | M | |