| School | Roll number | County | Total (latest year) | Latest average class size | Largest class | Classes 30+ |
|---|---|---|---|---|---|---|
| St Cóman's Wood Primary School | 20498B | Roscommon | 605 | 22.38 | 28 | 0 |
| Abbey Primary School | 20573M | Roscommon | 427 | 26.12 | 30 | 1 |
| S N Cluain na Cille | 18395C | Roscommon | 399 | 24.94 | 29 | 0 |
| TARMON N S | 13757I | Roscommon | 276 | 27.33 | 36 | 5 |
| ROXBORO N S | 18742U | Roscommon | 226 | 25.11 | 30 | 1 |
| BALLYBAY NATIONAL SCHOOL | 19534S | Roscommon | 224 | 24.22 | 30 | 1 |
| S N CNOC AN SAMHRAIDH | 12754U | Roscommon | 223 | 20.80 | 24 | 0 |
| S N Cor na Fola B | 01607T | Roscommon | 223 | 22.30 | 30 | 1 |
| S N CRUACHAIN | 18012G | Roscommon | 173 | 20.57 | 27 | 0 |
| ROOSKEY N S | 04800F | Roscommon | 160 | 26.67 | 34 | 1 |
| N MICHEAL AGUS PADRAIG | 19720P | Roscommon | 156 | 25.00 | 33 | 1 |
| S N AN GLEANN DUIBH | 18626S | Roscommon | 147 | 24.50 | 29 | 0 |
| ST ANNES CON N S | 13198V | Roscommon | 141 | 17.71 | 25 | 0 |
| ABBEYCARTON NS | 19809I | Roscommon | 138 | 23.00 | 28 | 0 |
| S N CNOC AN CHROCAIRE | 18571T | Roscommon | 136 | 19.67 | 26 | 0 |
| ST MARY'S PRIMARY | 17808T | Roscommon | 136 | 24.80 | 28 | 0 |
| Scoil Bhríde | 19815D | Roscommon | 126 | 25.20 | 31 | 1 |
| S N NAOMH SEOSAMH | 12964I | Roscommon | 121 | 24.20 | 30 | 1 |
| LISANISKEY N S | 14356S | Roscommon | 108 | 21.60 | 28 | 0 |
| ATHLEAGUE N S | 15308M | Roscommon | 105 | 26.25 | 28 | 0 |
| S N PADRAIG NAOFA | 17748E | Roscommon | 104 | 20.80 | 28 | 0 |
| S N BAILE UI FHIDHNE | 18432F | Roscommon | 96 | 24.00 | 34 | 1 |
| S N LIOS A CUILL M | 13047A | Roscommon | 94 | 23.50 | 26 | 0 |
| WHITEHALL N S | 14049J | Roscommon | 93 | 23.25 | 30 | 1 |
| Dangan NS | 17571O | Roscommon | 92 | 23.00 | 24 | 0 |
| S N NAOMH TREASA | 18454P | Roscommon | 89 | 22.25 | 29 | 0 |
| St. Bride's N.S. | 16334S | Roscommon | 89 | 22.25 | 26 | 0 |
| Cloontuskert National School | 18116S | Roscommon | 82 | 20.50 | 27 | 0 |
| S N ARD CIANAIN | 17054R | Roscommon | 77 | 19.25 | 30 | 1 |
| TULSK N S | 16034G | Roscommon | 77 | 19.25 | 22 | 0 |
| SCOIL MHUIRE | 18061T | Roscommon | 69 | 17.25 | 20 | 0 |
| BRIDESWELL N S | 15413J | Roscommon | 68 | 22.67 | 27 | 0 |
| S N POL NAOFA | 01086R | Roscommon | 66 | 22.00 | 24 | 0 |
| CIARAN NAOFA | 18194P | Roscommon | 60 | 20.00 | 21 | 0 |
| BALLYFORAN MIXED N S | 01866U | Roscommon | 59 | 18.00 | 21 | 0 |
| BALLANAGARE N S | 17266J | Roscommon | 57 | 19.00 | 21 | 0 |
| S N MHUIRE LOURDES | 18536R | Roscommon | 57 | 19.00 | 22 | 0 |
| TIBOHINE N S | 15543W | Roscommon | 56 | 18.67 | 23 | 0 |
| TISRARA NATIONAL SCHOOL | 18165I | Roscommon | 54 | 18.00 | 23 | 0 |
| CLOVER HILL N S | 13262E | Roscommon | 51 | 15.00 | 18 | 0 |
| S N NAOMH EOIN | 14925I | Roscommon | 47 | 15.67 | 17 | 0 |
| BALLINTLEVA N S | 18729F | Roscommon | 46 | 15.33 | 19 | 0 |
| GORTHAGANNY N S | 16127N | Roscommon | 45 | 15.00 | 18 | 0 |
| S N CILL TROSTAIN | 17353E | Roscommon | 45 | 15.00 | 16 | 0 |
| CASTLEPLUNKETT N S | 15545D | Roscommon | 44 | 22.00 | 23 | 0 |
| CLOONIQUIN N S | 18027T | Roscommon | 44 | 22.00 | 22 | 0 |
| S N NAOMH PADRAIG | 15045G | Roscommon | 44 | 13.67 | 17 | 0 |
| CLOONFOUR N S | 13498K | Roscommon | 42 | 21.00 | 22 | 0 |
| CARRICK N S | 13839K | Roscommon | 41 | 18.00 | 23 | 0 |
| FAIRYMOUNT N S | 15425Q | Roscommon | 39 | 19.50 | 24 | 0 |
| DON N S | 15255R | Roscommon | 38 | 19.00 | 21 | 0 |
| NAOMH ATRACHTA | 18182I | Roscommon | 36 | 18.00 | 22 | 0 |
| THREEN N S | 10967E | Roscommon | 35 | 17.50 | 20 | 0 |
| GRANGE N S | 15584N | Roscommon | 32 | 16.00 | 18 | 0 |
| KILTEEVAN N S | 14966W | Roscommon | 32 | 16.00 | 17 | 0 |
| AUGHRIM N S | 14684M | Roscommon | 31 | 15.50 | 18 | 0 |
| CLONOWN N S | 16427C | Roscommon | 28 | 14.00 | 19 | 0 |
| CLOONBONNIF N S | 11242L | Roscommon | 24 | 12.00 | 15 | 0 |
| MOUNT TALBOT N S | 14056G | Roscommon | 24 | 12.00 | 16 | 0 |
| S N MICHIL NAOFA | 05220P | Roscommon | 24 | 12.00 | 17 | 0 |
| CLOONCAGH N S | 16291D | Roscommon | 20 | 10.00 | 13 | 0 |
| S N NAOMH PADRAIG | 11201U | Roscommon | 18 | 9.00 | 11 | 0 |
| S N RATH ARADH | 17100V | Roscommon | 17 | 8.50 | 11 | 0 |
| S N O DUBHLAIN | 17849K | Roscommon | 15 | 7.50 | 9 | 0 |
| S N NAOMH CEITHEACH | 16815L | Roscommon | 13 | 6.50 | 9 | 0 |
| SCOIL MHUIRE GAN SMAL | 18005J | Roscommon | 13 | 6.50 | 8 | 0 |
| LISMOIL N S | 11466K | Roscommon | 12 | 6.00 | 6 | 0 |
| S N NAOMH MHUIRE | 17709R | Roscommon | 9 | 4.50 | 6 | 0 |
| SLATTA N S | 13879W | Roscommon | 8 | 4.00 | 5 | 0 |