| Name | What | Region | Country | Lat | Long | Elev Ft. | Pop Est |
|---|
| Cadamstown | city | County Offaly | Ireland | 53.1252778 | -7.6583333 | 518 | 2686 |
| Cangort | city | County Offaly | Ireland | 52.9888889 | -7.9702778 | 360 | 2747 |
| Cappagowlan | city | County Offaly | Ireland | 53.1763889 | -7.6569444 | 265 | 2675 |
| Cappanageeragh | city | County Offaly | Ireland | 53.2722222 | -7.3669444 | 272 | 2655 |
| Capppancur | city | County Offaly | Ireland | 53.27 | -7.4316667 | 242 | 2668 |
| Cappyroe | city | County Offaly | Ireland | 53.2758333 | -7.3902778 | 249 | 2661 |
| Carrick | city | County Offaly | Ireland | 53.1930556 | -7.9019444 | 262 | 2660 |
| Cartland Bridge | city | County Offaly | Ireland | 53.3411111 | -7.1055556 | 351 | 3367 |
| Castletown | city | County Offaly | Ireland | 53.0688889 | -7.8394444 | 328 | 2668 |
| Castletown | city | County Offaly | Ireland | 53.3144444 | -7.7511111 | 387 | 2725 |
| Charlestown | city | County Offaly | Ireland | 53.3397222 | -7.6030556 | 232 | 2737 |
| Cill Aichidh | city | County Offaly | Ireland | 53.2133333 | -7.4494444 | 351 | 2679 |
| Cill Chormaic | city | County Offaly | Ireland | 53.1741667 | -7.7255556 | 249 | 2660 |
| Cionn Eitigh | city | County Offaly | Ireland | 53.0955556 | -7.7213889 | 534 | 2664 |
| Clara | city | County Offaly | Ireland | 53.3425 | -7.6138889 | 232 | 2737 |
| Clareen | city | County Offaly | Ireland | 53.0705556 | -7.7955556 | 403 | 2668 |
| Cloghal | city | County Offaly | Ireland | 53.2508333 | -7.9761111 | 180 | 2658 |
| Cloghan | city | County Offaly | Ireland | 53.2216667 | -7.8841667 | 249 | 2657 |
| Cloghatanny | city | County Offaly | Ireland | 53.345 | -7.6752778 | 229 | 2759 |
| Cloirtheach | city | County Offaly | Ireland | 53.3425 | -7.6138889 | 232 | 2737 |
| Clonaderg | city | County Offaly | Ireland | 53.3375 | -7.8861111 | 305 | 2743 |
| Clonarrow | city | County Offaly | Ireland | 53.2852778 | -7.2569444 | 275 | 2654 |
| Clonavoe | city | County Offaly | Ireland | 53.2580556 | -7.1516667 | 259 | 2654 |
| Clonbrown | city | County Offaly | Ireland | 53.2558333 | -7.0655556 | 255 | 3401 |
| Clonbulloge | city | County Offaly | Ireland | 53.2616667 | -7.0880556 | 249 | 2720 |
| Cloncanon | city | County Offaly | Ireland | 53.3225 | -7.0477778 | 301 | 3443 |
| Cloncreen | city | County Offaly | Ireland | 53.27 | -7.1225 | 252 | 2720 |
| Clondelara | city | County Offaly | Ireland | 53.27 | -7.9941667 | 180 | 2658 |
| Cloneen | city | County Offaly | Ireland | 53.3469444 | -7.35 | 469 | 2894 |
| Clonlack | city | County Offaly | Ireland | 53.3325 | -7.1922222 | 367 | 2651 |
| Clonmacnoise | city | County Offaly | Ireland | 53.3252778 | -7.9794444 | 193 | 2402 |
| Clonmore | city | County Offaly | Ireland | 53.2672222 | -7.3825 | 252 | 2661 |
| Clonmore | city | County Offaly | Ireland | 53.3861111 | -7.1269444 | 377 | 3217 |
| Clonmore Cross Roads | city | County Offaly | Ireland | 53.3802778 | -7.1077778 | 364 | 3889 |
| Clonona | city | County Offaly | Ireland | 53.2352778 | -7.925 | 219 | 2672 |
| Clonony | city | County Offaly | Ireland | 53.2352778 | -7.925 | 219 | 2672 |
| Clonroosk | city | County Offaly | Ireland | 53.25 | -7.0680556 | 252 | 4213 |
| Clonsast | city | County Offaly | Ireland | 53.21 | -7.15 | 255 | 2925 |
| Clonsast Lower | city | County Offaly | Ireland | 53.21 | -7.15 | 255 | 2925 |
| Clonygowan | city | County Offaly | Ireland | 53.1875 | -7.2788889 | 301 | 2675 |
| Clonyquin | city | County Offaly | Ireland | 53.175 | -7.2894444 | 308 | 2675 |
| Clortrane | city | County Offaly | Ireland | 53.3013889 | -8.0122222 | 183 | 2249 |
| Cluain Bolg | city | County Offaly | Ireland | 53.2616667 | -7.0880556 | 249 | 2720 |
| Cluain Mnic Nois | city | County Offaly | Ireland | 53.3252778 | -7.9794444 | 193 | 2402 |
| Cluain Mnic Nóis | city | County Offaly | Ireland | 53.3252778 | -7.9794444 | 193 | 2402 |
| Cluain na nGamhan | city | County Offaly | Ireland | 53.1875 | -7.2788889 | 301 | 2675 |
| Clóirtheach | city | County Offaly | Ireland | 53.3425 | -7.6138889 | 232 | 2737 |
| Codd | city | County Offaly | Ireland | 53.3052778 | -7.0411111 | 278 | 4894 |
| Coffey's Cross Bridge | city | County Offaly | Ireland | 53.0516667 | -7.8694444 | 291 | 2668 |
| Coffeyʼs Cross Bridge | city | County Offaly | Ireland | 53.0516667 | -7.8694444 | 291 | 2668 |
| Cogran | city | County Offaly | Ireland | 53.1816667 | -8.0236111 | 183 | 2695 |
| Coolaghansglaster | city | County Offaly | Ireland | 53.1369444 | -7.9705556 | 203 | 2709 |
| Coolcor | city | County Offaly | Ireland | 53.3675 | -7.2138889 | 446 | 2686 |
| Coolderry | city | County Offaly | Ireland | 53.083333 | -7.8391667 | 272 | 2668 |
| Coole | city | County Offaly | Ireland | 53.3297222 | -7.2536111 | 462 | 2653 |
| Corndarragh | city | County Offaly | Ireland | 53.2888889 | -7.4513889 | 249 | 2668 |
| Corolanty | city | County Offaly | Ireland | 53.091667 | -7.9277778 | 223 | 2730 |
| County Bridge | city | County Offaly | Ireland | 53.1383333 | -7.6416667 | 521 | 2686 |
| Cranereagh Bridge | city | County Offaly | Ireland | 53.1952778 | -7.8819444 | 246 | 2660 |
| Cree | city | County Offaly | Ireland | 53.0597222 | -7.8577778 | 295 | 2668 |
| Creggan | city | County Offaly | Ireland | 53.285 | -7.8663889 | 203 | 2654 |
| Crinkill | city | County Offaly | Ireland | 53.0772222 | -7.8972222 | 242 | 2690 |
| Crinkle | city | County Offaly | Ireland | 53.0772222 | -7.8972222 | 242 | 2690 |
| Croghan | city | County Offaly | Ireland | 53.3405556 | -7.2772222 | 639 | 2729 |
| Cross Keys Cross Roads | city | County Offaly | Ireland | 53.2436111 | -7.3772222 | 272 | 2684 |
| Cullenwane Cross Roads | city | County Offaly | Ireland | 52.8969444 | -7.9708333 | 426 | 2738 |
| Cully | city | County Offaly | Ireland | 53.24 | -7.6561111 | 246 | 2658 |
| Cumber Lower | city | County Offaly | Ireland | 53.0772222 | -7.7275 | 633 | 2673 |
| Curragh | city | County Offaly | Ireland | 53.2430556 | -7.3438889 | 265 | 2677 |
| Curralanty Cross Roads | city | County Offaly | Ireland | 53.08333 | -7.9244444 | 226 | 2742 |
| Cushaling | city | County Offaly | Ireland | 53.2897222 | -7.0458333 | 262 | 3401 |
| Cushina | city | County Offaly | Ireland | 53.1944444 | -7.1652778 | 262 | 3144 |
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