| School | Roll number | County | Total (latest year) | Latest average class size | Largest class | Classes 30+ |
|---|---|---|---|---|---|---|
| ST JOSEPHS CONVENT | 18178R | Longford | 527 | 17.75 | 23 | 0 |
| ST MATTHEWS MIXED N.S | 20128O | Longford | 373 | 23.27 | 31 | 2 |
| ST MARYS N.S. | 20124G | Longford | 352 | 21.13 | 25 | 0 |
| SCOIL MHUIRE N S | 19987J | Longford | 317 | 24.38 | 34 | 3 |
| S N NAOMH TREASA | 19279F | Longford | 306 | 21.69 | 32 | 3 |
| S N CNOC AN MHARCAIGH | 07518E | Longford | 289 | 24.08 | 36 | 4 |
| The Sacred Heart Primary NS | 20101R | Longford | 250 | 17.85 | 22 | 0 |
| STONEPARK N S | 14386E | Longford | 239 | 23.90 | 32 | 4 |
| SCOIL NAOMH MICHEAL | 00856M | Longford | 224 | 18.67 | 25 | 0 |
| ST MARYS MIXED N S | 16665S | Longford | 215 | 23.22 | 33 | 1 |
| St Emer's National School | 19753H | Longford | 215 | 19.55 | 29 | 0 |
| SAINT MELS | 19467G | Longford | 180 | 22.50 | 28 | 0 |
| S N NAOMH COLMCILLE | 19296F | Longford | 155 | 24.33 | 28 | 0 |
| SAMHTHANN N S | 17561L | Longford | 145 | 23.33 | 26 | 0 |
| FERMOYLE MIXED N S | 13320P | Longford | 112 | 22.40 | 27 | 0 |
| GAELSCOIL AN LONGFOIRT | 20083S | Longford | 112 | 17.67 | 22 | 0 |
| NAOMH DOMINIC N S | 15154L | Longford | 109 | 21.80 | 28 | 0 |
| ST PATRICKS NS LONGFORD | 19353O | Longford | 108 | 21.60 | 27 | 0 |
| COLEHILL MIXED N S | 14672F | Longford | 96 | 24.00 | 28 | 0 |
| S N MHUIRE | 18733T | Longford | 94 | 23.50 | 28 | 0 |
| Lanesborough Primary School | 18259R | Longford | 88 | 19.25 | 24 | 0 |
| S N AN LEANA MOR | 05115S | Longford | 69 | 22.00 | 28 | 0 |
| ST. JOHNS NATIONAL SCHOOL | 12683A | Longford | 67 | 16.75 | 19 | 0 |
| S N NAOMH MHUIRE | 19171I | Longford | 64 | 21.33 | 28 | 0 |
| ST PATRICKS | 19975C | Longford | 63 | 21.00 | 25 | 0 |
| NAOMH PADRAIG N S | 13752V | Longford | 57 | 19.00 | 26 | 0 |
| ST COLUMBAS MXD N S | 12813K | Longford | 56 | 18.67 | 27 | 0 |
| SCOIL BHRÍDE | 12136R | Longford | 52 | 17.33 | 21 | 0 |
| SCOIL MHUIRE | 17644P | Longford | 45 | 15.00 | 20 | 0 |
| NAOMH GUASACHTA N S | 12736S | Longford | 44 | 14.67 | 18 | 0 |
| KILLASONNA MIXED N S | 14300O | Longford | 41 | 20.50 | 24 | 0 |
| NAOMH EARNAIN N S | 18258P | Longford | 29 | 14.50 | 18 | 0 |
| ST BERNARDS MIXED N S | 15122V | Longford | 29 | 14.50 | 17 | 0 |
| FORGNEY N S | 00860D | Longford | 23 | 11.50 | 16 | 0 |
| TASHINNY N S | 10223C | Longford | 23 | 11.50 | 12 | 0 |
| St. John's National School, | 13313S | Longford | 19 | 9.50 | 12 | 0 |
| CLOONTAGH MIXED N S | 14650S | Longford | 14 | 7.00 | 9 | 0 |