| A mari usque ad mare | |
| Acer | | The maple tree (L.) |  | RCIC | |
| Acer acerpori | | As the maple, so the sapling (L.) |  | RCACC | |
| Action from knowledge | |
| Adsum | |
| Advance | |
| Aere perennius | |
| Airaghardt | |
| Air son ar duthchais | |
| Ake ake kia kaha | |
| Albainn gu brath | |
| Amor patriae | |
| Animo et fide | |
| Arma pacis fulcra | | Armed strength for peace (L.) |  | HAC | |
| Arte et marte | | By skill and by fighting (L.) |  | REME |  | EME | |
| Aucto splendore resurgo | |
| Audax et cautus | |
| Auspicium melioris aevi | |
| Aut cursu, aut cominus armis | |