| School | Roll number | County | Total (latest year) | Latest average class size | Largest class | Classes 30+ |
|---|---|---|---|---|---|---|
| QUIGNAMANGER N S | 15257V | Mayo | 364 | 24.27 | 34 | 3 |
| CULLENS N S | 07054L | Mayo | 273 | 23.82 | 29 | 0 |
| Scoil Íosa | 20275E | Mayo | 242 | 17.62 | 22 | 0 |
| CROSSMOLINA N.S. | 20125I | Mayo | 235 | 25.56 | 30 | 1 |
| SCOIL CHOLMCILLE | 15555G | Mayo | 231 | 25.11 | 31 | 3 |
| BEHEYMORE N S | 11725I | Mayo | 228 | 27.75 | 29 | 0 |
| St Joseph's NS | 18561Q | Mayo | 217 | 22.11 | 31 | 1 |
| S N NAOMH PADRAIG | 12206M | Mayo | 148 | 24.67 | 32 | 1 |
| SN CROI MUIRE | 17727T | Mayo | 127 | 25.40 | 30 | 1 |
| KILLALA N S | 16811D | Mayo | 85 | 20.00 | 31 | 1 |
| CORCLOUGH NS | 15014S | Mayo | 79 | 19.75 | 22 | 0 |
| S N LEATH ARDAN | 16911H | Mayo | 76 | 19.00 | 21 | 0 |
| Ardagh National School | 20576S | Mayo | 73 | 18.25 | 23 | 0 |
| SCOIL NAOMH BRID | 14290O | Mayo | 67 | 22.33 | 24 | 0 |
| SN INBHEAR | 12568A | Mayo | 67 | 22.33 | 24 | 0 |
| Kilmurry NS | 20513R | Mayo | 65 | 16.25 | 19 | 0 |
| S N EACHLEIME | 12373I | Mayo | 64 | 21.33 | 25 | 0 |
| SN GLEANN A CHAISIL | 13222P | Mayo | 64 | 16.33 | 18 | 0 |
| SCOIL CHROÍ RÓ NAOFA BEANNCHOR IORRAIS | 13684H | Mayo | 61 | 20.33 | 22 | 0 |
| COONEAL N.S. | 17209U | Mayo | 58 | 19.33 | 22 | 0 |
| S N BEAL AN MHUIRTHEAD | 17923T | Mayo | 58 | 19.33 | 21 | 0 |
| RATHBANE N S | 15996N | Mayo | 57 | 19.00 | 23 | 0 |
| S N ACHAIDH AN GHLAISIN | 18594I | Mayo | 48 | 16.00 | 21 | 0 |
| TEMPLEMARY N S | 13758K | Mayo | 47 | 15.67 | 21 | 0 |
| Bunscoil Naomh Bríd agus Pádraíg | 20552E | Mayo | 46 | 15.33 | 21 | 0 |
| CORMAIC NFA | 13225V | Mayo | 38 | 19.00 | 23 | 0 |
| MOUNT PALMER NATIONAL SCHOOL | 20217N | Mayo | 37 | 18.50 | 24 | 0 |
| DRUMGALLAGH N S | 18002D | Mayo | 33 | 16.50 | 18 | 0 |
| GEESALA CENTRAL SCHOOL | 19776T | Mayo | 29 | 14.50 | 15 | 0 |
| KNOCKANILLO N S | 16562I | Mayo | 28 | 14.00 | 17 | 0 |
| S N POL A TSOMAIS | 16283E | Mayo | 27 | 13.50 | 16 | 0 |
| S N ROS DUMHACH | 12569C | Mayo | 27 | 13.50 | 17 | 0 |
| S N Dhumha Thuama | 14193Q | Mayo | 26 | 13.00 | 16 | 0 |
| SN Cholmcille, Ceathrú Thaidhg | 20588C | Mayo | 26 | 13.00 | 13 | 0 |
| GARRACLOON N S | 06852L | Mayo | 25 | 12.50 | 14 | 0 |
| Lacken National School | 20512P | Mayo | 25 | 8.33 | 9 | 0 |
| BARNATRA N S | 14188A | Mayo | 24 | 12.00 | 12 | 0 |
| CILL MHOR IORRAIS | 14258S | Mayo | 20 | 10.00 | 10 | 0 |
| S N AN TSRAITH | 13383Q | Mayo | 15 | 7.50 | 8 | 0 |
| CLOONDAFF N S | 11834N | Mayo | 11 | 5.50 | 6 | 0 |
| Scoil Néifinn | 20431P | Mayo | 11 | 5.50 | 7 | 0 |
| CLOGHANS N S | 16170O | Mayo | 9 | 4.50 | 5 | 0 |
| S N DRUIM SLAOD | 17532E | Mayo | 8 | 4.00 | 4 | 0 |