| Competition: | Primera División de México |
| Season: | 2005−06 |
| Winners: | Toluca (8th title) |
| Continentalcup1: | Champions' Cup |
| Continentalcup1 Qualifiers: | Toluca |
| Continentalcup2: | Copa Libertadores |
| Continentalcup2 Qualifiers: | UNAM UANL Guadalajara (First Stage) |
| Continentalcup3: | Copa Sudamericana |
| Continentalcup3 Qualifiers: | Toluca |
| League Topscorer: | Sebastian Abreu Kléber Boas Walter Gaitán Vicente Matías Vuoso (11 goals) |
| Prevseason: | Clausura 2005 |
| Nextseason: | Clausura 2006 |
Primera División de México (Mexican First Division) Apertura 2005 was the 2005 edition of the Primera Division de Mexico, crowning Mexico's fall champion in football. The season ran from August to December 2005. San Luis was promoted to the Primera División de México thus, Puebla was relegated to the Primera División A. Toluca won the championship and qualified for the CONCACAF Champions' Cup 2006.
Players sorted first by goals scored, then by last name. Only regular season goals listed.
| Rank | Player | Club | Goals | ||
|---|---|---|---|---|---|
| align=center rowspan=4 | 1 | Sebastian Abreu | Sinaloa | align=center rowspan=4 | 11 |
 Kléber Boas | América | ||||
 Walter Gaitán | UANL | ||||
| Vicente Matías Vuoso | Santos Laguna | ||||
| align=center rowspan=7 | 5 | Salvador Cabañas | Chiapas | align=center rowspan=7 | 9 |
| César Delgado | Cruz Azul | ||||
 Guillermo Franco | Monterrey | ||||
| Patricio Galaz | Atlante | ||||
| Daniel Ludueña | UAG | ||||
| Carlos Ochoa | Chiapas | ||||
| Rodrigo Ruiz | Santos Laguna |
Source: MedioTiempo
Monterrey won 7–0 on aggregate.----
UANL won 5–4 on aggregate.----
Toluca won 1–0 on aggregate.----
Pachuca won 4–0 on aggregate.
2–2 on aggregate. Monterrey advanced for being the higher seeded team.----
Toluca won 2–1 on aggregate.
Toluca won 6–3 on aggregate.