2017–18 Gamma Ethniki
The 2017–18 Gamma Ethniki was the 35th season since the official establishment of the third tier of Greek football in 1983.
It started on 1 October 2017. After the finish of the eight groups, the first team of each group will qualify for a playoff round of two groups, to determine which four teams will be promoted to Football League.
97 teams were divided into eight groups according to geographical criteria.
Panelefsiniakos, AO Chania, AEL Kalloni, Panthrakikos, Eordaikos, A.E. Istiaia, Mavroi Aetoi Eleftherochori, Amvrakia Kostakioi, APO Kanaris Nenita, Pyrsos Grevena, AO Syros, Poseidon Neoi Poroi and AO Polykratis Pythagoreio withdrew from the league before the group draw.
Group 1
Teams
| Team | Location | Last season |
| Nestos Chrysoupoli | Chrysoupoli | |
| Doxa Proskinites | Proskinites | |
| Orfeas Xanthi | Xanthi | |
| Kavala | Kavala | |
| Apollon Paralimnio | Paralimnio | |
| A.E. Didymoteicho | Didymoteicho | |
| Doxa Neo Sidirochori | Neo Sidirochori | |
| Megas Alexandros Xiropotamos | Xiropotamos | |
| Aetos Orfano | Ofrynio | |
| Elpis Skoutari | Skoutari | promoted as Amateur Cup finalist |
| Megas Alexandros Karperi | Karperi | |
| Aris Avato | Avato |
Standings
Group 2
Teams
| Team | Location | Last season |
| Pierikos | Katerini | |
| APE Langadas | Langadas | |
| Kampaniakos | Chalastra | |
| AO Kardia | Kardia | |
| Almopos Aridea | Aridaea | |
| Naoussa | Naousa | |
| Makedonikos | Efkarpia | |
| Agrotikos Asteras | Evosmos | |
| Kilkisiakos | Kilkis | |
| Edessaikos | Edessa | |
| Aris Palaiochori | Palaiochori | |
| Megas Alexandros Trikala | Trikala Imathia | |
| Philippos Alexandreia | Alexandreia | |
| AE Karitsa | Karitsa | |
| Iraklis Thessaloniki | Thessaloniki |
Standings
Group 3
Teams
| Team | Location | Last season |
| Thesprotos | Igoumenitsa | |
| Tilikratis | Lefkada | |
| Ethnikos Filippiada | Filippiada | |
| Makedonikos Foufas | Foufas | |
| Doxa Kranoula | Kranoula | |
| Asteras Parapotamos | Parapotamos | |
| Skoufas Kompoti | Kompoti | |
| Panlefkadios | Lefkada | |
| A.E. Lefkimmi | Lefkimmi | |
| Neos Amfilochos | Amfilochia | |
| AEP Karagiannia | Karagiannia | |
| Ermis Amyntaio | Amyntaio |
Standings
Group 4
Teams
| Team | Location | Last season |
| Niki Volos | Nea Ionia Volos | |
| Olympiacos Volos | Volos | |
| Rigas Feraios | Velestino | |
| Thiva | Thiva | |
| Opountios | Martino | |
| Achilleas Farsala | Farsala | |
| Digenis Neochori | Oichalia | |
| Almyros | Almyros | |
| APOK Velouchi | Karpenisi | |
| Asteras Itea | Itea | |
| APO Amvrysseas | Distomo | |
| AO Sellana | Sellana | |
| Volos NFC | Volos |
Standings
Group 5
Teams
| Team | Location | Last season |
| Achaiki | Kato Achaia | |
| PAO Varda | Varda | |
| Asteras Amaliada | Amaliada | |
| Tsiklitiras Pylos | Pylos | |
| Panarkadikos | Tripoli | |
| Kalamata | Kalamata | |
| Zakynthos | Zakynthos | |
| Paniliakos | Pyrgos | |
| Pallixouriakos | Lixouri | |
| Diagoras Vrachnaiika | Vrachnaiika | |
| Asteras Vlachioti | Vlachioti | |
| Leonidio | Leonidio |
Standings
Group 6
Teams
| Team | Location | Last season |
| Ionikos | Nikaia | |
| Ethnikos Piraeus | Piraeus | |
| Proodeftiki | Nikaia | |
| Rodos | Rhodes | |
| Ialysos | Ialysos | |
| Zevgolateio | Zevgolateio | |
| A.O.Loutraki | Loutraki | |
| Keratsini | Keratsini | |
| Pelopas Kiato | Kiato | |
| Diagoras | Rhodes | |
| Enosi Panaspropyrgiakou Doxas | Aspropyrgos |
Standings
Group 7
Teams
| Team | Location | Last season |
| Enosi Ermionida | Kranidi | |
| Panargiakos | Argos | |
| Aiolikos | Mytilene | |
| Chalkida | Chalkida | |
| Panthiraikos | Santorini | |
| Thyella Rafina | Rafina | |
| Triglia Rafina | Rafina | |
| Ermis Kiveri | Kiveri | |
| Aittitos Spata | Spata | |
| Diagoras Agia Paraskevi | Agia Paraskevi, Lesbos | |
| Tamyniakos | Aliveri |
Standings
Group 8
Teams
| Team | Location | Last season |
| Fostiras | Tavros | |
| Agios Ierotheos | Peristeri | |
| A.E. Kifisia | Kifisia | |
| Ilisiakos | Zografou | |
| Ermis Zoniana | Zoniana | |
| Atsalenios | Heraklion | |
| Irodotos | Nea Alikarnassos | |
| Egaleo | Egaleo | |
| OF Ierapetra | Ierapetra | |
| AE Mylopotamos | Mylopotamos | |
| Palaiochora | Palaiochora |