Lorient AgglomérationComposition
The communauté d'agglomération consists of the following 25 communes:[1][3]
The areas and populations (as per INSEE estimates as at 1 January 2020) are as follows:
| Name | Agglomeration | Area in km2 | Population 2020 estimate |
| Lorient | Lorient | 14.48 | 57,412 |
| Ploemeur | Lorient | 39.72 | 18,537 |
| Larmor-Plage | Lorient | 7.27 | 8,277 |
| Quéven | Lorient | 23.93 | 8,816 |
| Lanester | Lorient | 18.37 | 22,940 |
| Caudan | Lorient | 42.63 | 7,091 |
| Total | Lorient | 149.40 | 123,073 |
| Hennebont | Hennebont | 18.57 | 15,873 |
| Inzinzac-Lochrist | Hennebont | 44.67 | 6,535 |
| Total | Hennebont | 63.24 | 22,408 |
| Riantec | Riantec-Locmiquélic | 14.06 | 5,806 |
| Locmiquélic | Riantec-Locmiquélic | 3.58 | 4,056 |
| Port-Louis | Riantec-Locmiquélic | 1.07 | 2,672 |
| Total | Riantec-Locmiquélic | 18.71 | 12,534 |
| Guidel | Guidel | 52.29 | 11,743 |
| Languidic | Languidic | 109.10 | 8,047 |
| Plouay | Plouay | 67.33 | 5,789 |
| Pont-Scorff | Pont-Scorff | 23.50 | 3,897 |
| Cléguer | | 32.15 | 3,310 |
| Gestel | | 6.25 | 2,609 |
| Bubry | | 69.09 | 2,289 |
| Groix (island) | | 14.82 | 2,256 |
| Inguiniel | | 51.40 | 2,193 |
| Brandérion | | 6.03 | 1,466 |
| Quistinic | | 42.95 | 1,421 |
| Calan | | 12.29 | 1,247 |
| Lanvaudan | | 18.30 | 804 |
| Gâvres | | 1.88 | 679 |
| Totals | | 738.73 | 205,765 |