A1 Ethnikis ya da uluslararası pazarlama adıyla Basket League, Yunanistan’daki 1. kademe profesyonel basketbol ligi. HEBA, tarafından organize edilmektedir. Sponsorluk anlaşmaları dolayısıyla Yunan Basketbol Ligi OPAP olarak da bilinmektedir.
Lig, Euroleague ulusal basketbol ligleri sıralaması’nda 3. sırada yer almaktadır. 14 takımdan oluşmaktadır. Ekim’den Haziran’a kadar maçlar yapılmaktadır. Takımlar normal sezonda 26 maç yaparlar ve ilk 8 takım play-off mücadelesi verir. İlk resmî Yunan Basketbol Şampiyonası 1926-27 sezonunda yapılmıştır.
| Şampiyon Takım | Şampiyonluk |
| Panathinaikos | 39 |
| Olympiacos BC | 13 |
| Aris BC | 10 |
| AEK BC | 8 |
| Panellinios | 6 |
| PAOK BC | 2 |
| Iraklis | 2 |
| Athens University | 1 |
| Near East | 1 |
| Sezon | Şampiyon Takım (Baş Antrenör) | Final Skor (Final MVP) | Finalist |
|---|---|---|---|
| 1986–87 | Aris BC Giannis Ioannidis | 3–0 Nikos Galis (Aris) | Panionios |
| 1987–88 | Aris BC Giannis Ioannidis | 3–0 Nikos Galis (Aris) | PAOK |
| 1988–89 | Aris BC Giannis Ioannidis | 3–1 Nikos Galis (Aris) | PAOK |
| 1989–90 | Aris BC Giannis Ioannidis | Nikos Galis (Aris) | PAOK |
| 1990–91 | Aris BC Michalis Kyritsis | 4–2 Nikos Galis (Aris) | PAOK |
| 1991–92 | PAOK Dušan Ivković | 4–1 Panagiotis Fasoulas (PAOK) | Olympiacos |
| 1992–93 | Olympiacos Giannis Ioannidis | 3–1 Georgios Sigalas (Olympiacos) | Panathinaikos |
| 1993–94 | Olympiacos Giannis Ioannidis | 3–2 Georgios Sigalas (Olympiacos) | PAOK Bravo |
| 1994–95 | Olympiacos Giannis Ioannidis | 3–2 Georgios Sigalas (Olympiacos) | Panathinaikos |
| 1995–96 | Olympiacos Giannis Ioannidis | 3–2 Georgios Sigalas (Olympiacos) | Panathinaikos |
| 1996–97 | Olympiacos Dušan Ivković | 3–1 Georgios Sigalas (Olympiacos) | AEK |
| 1997–98 | Panathinaikos Slobodan Subotić | 3–2 Dino Rađja (Panathinaikos) | PAOK |
| 1998–99 | Panathinaikos Slobodan Subotić | 3–2 Dejan Bodiroga (Panathinaikos) | Olympiacos |
| 1999–00 | Panathinaikos Željko Obradović | 3–0 Dejan Bodiroga (Panathinaikos) | PAOK |
| 2000–01 | Panathinaikos Željko Obradović | 3–2 Željko Rebrača (Panathinaikos) | Olympiacos |
| 2001–02 | AEK BC Dragan Šakota | 3–2 Dimos Dikoudis (AEK) | Olympiacos |
| 2002–03 | Panathinaikos Željko Obradović | 3–1 Jaka Lakovič (Panathinaikos) | AEK |
| 2003–04 | Panathinaikos Željko Obradović | 3–0 Nikos Chatzivrettas (Panathinaikos) | Maroussi TIM |
| 2004–05 | Panathinaikos Željko Obradović | 3–1 Jaka Lakovič (Panathinaikos) | AEK |
| 2005–06 | Panathinaikos Željko Obradović | 3–0 Dimitris Diamantidis (Panathinaikos) | Olympiacos |
| 2006–07 | Panathinaikos Željko Obradović | 3–2 Dimitris Diamantidis (Panathinaikos) | Olympiacos |
| 2007–08 | Panathinaikos Željko Obradović | 3–2 Dimitris Diamantidis (Panathinaikos) | Olympiacos |
| 2008–09 | Panathinaikos Željko Obradović | 3–1 Dimitris Diamantidis (Panathinaikos) | Olympiacos |
| 2009–10 | Panathinaikos Željko Obradović | 3–1 Mike Batiste (Panathinaikos) | Olympiacos |
| 2010–11 | Panathinaikos Željko Obradović | 3–1 Dimitris Diamantidis (Panathinaikos) | Olympiacos |
| 2011–12 | Olympiacos Dušan Ivković | 3–2 Vassilis Spanoulis (Olympiacos) | Panathinaikos |
| 2012–13 | Panathinaikos Argyris Pedoulakis | 3–0 Stéphane Lasme (Panathinaikos) | Olympiacos |
| 2013–14 | Panathinaikos Fragiskos Alvertis | 3–2 Dimitris Diamantidis (Panathinaikos) | Olympiacos |
| 2014–15 | Olympiacos Ioannis Sfairopoulos | 3–0 Vassilis Spanoulis (Olympiacos) | Panathinaikos |
| 2015–16 | Olympiacos Ioannis Sfairopoulos | 3–1 Vassilis Spanoulis (Olympiacos) | Panathinaikos |
| 2016–17 | Panathinaikos Superfoods Xavi Pascual | 3–2 | Olympiacos BC |
| 2017–18 | Panathinaikos Superfoods Xavi Pascual | 3–2 | Olympiacos BC |
| 2018–19 | Panathinaikos OPAP Rick Pitino | 3–0 | Promitheas Patras |
| 2019–20 | Panathinaikos OPAP | Lig Sistemi | AEK Athens |
| 2020–21 | Panathinaikos OPAP Oded Katash | 3–1 | G.S. Lavrio B.C. |
| 2021–22 | Olympiacos BC Giorgos Bartzokas | 3–0 | Panathinaikos OPAP |
| 2022–23 |