2005–06 Argentine Primera División
The 2005–06 Argentine Primera División was the 115th season of top-flight football in Argentina. The season ran from 5 August 2005 to 14 May 2006.
Tiro Federal and Gimnasia y Esgrima de Jujuy were promoted from Primera B Nacional.
Boca Juniors won both, Apertura and Clausura championships totalising 28 league titles to date, while Instituto (C), Tiro Federal and Olimpo were relegated.
Relegation
Promotion playoff
| Series | Team 1 | Team 2 | 1st. leg | Venue 1 | City 1 | 2nd. leg | Venue 2 | City 2 | Agg. |
| 1 | Olimpo | Belgrano (C) | 1–2 | Chateau Carreras | Córdoba | 1–2 | Roberto Carminatti | Bahía Blanca | 4–2 |
| 2 | Argentinos Juniors | Huracán | 1–1 | Tomás A. Ducó | Buenos Aires | 2–2 | Diego A. Maradona | Buenos Aires |
''Belgrano de Córdoba promoted to Primera, while Argentinos Juniors remained in the top division by sporting advantage ''