| Competition: | Campeonato Nacional Clausura Petrobras |
| Dates: | 6 July – 9 December 2012 |
| Season: | 2012 |
| Winners: | Huachipato 2nd title |
| Relegated: | Deportes La Serena Unión San Felipe Universidad de Concepción (Rel. Play-off) |
| Continentalcup1: | 2013 Copa Libertadores |
| Continentalcup1 Qualifiers: | Huachipato Deportes Iquique (Agg. Table) |
| Continentalcup2: | 2013 Copa Sudamericana |
| Continentalcup2 Qualifiers: | Colo-Colo (Clau. Table) |
| League Topscorer: | Sebastián Sáez (13 goals) |
| Biggest Home Win: | Rangers 5–0 Deportes Iquique (27 July) |
| Highest Attendance: | 41,764 Colo-Colo 1–0 Universidad de Chile (21 October) |
| Attendance: | 887,191 |
| Average Attendance: | 5,312 |
| Matches: | 167 |
| Total Goals: | 468 |
| Prevseason: | 2012–A |
| Nextseason: | 2013–A |
The 2012 Campeonato Nacional Clausura Petrobras was the 91st season of the Chilean Primera División. The champion was Huachipato, winning their 2nd league title, 38 years after their first championship. It was, as of 2023, the last Chilean top-flight tournament to be decided by playoff stage.
Colo-Colo won 6–5 on aggregate.----Unión Española won 4–1 on aggregate.----Huachipato won 3–2 on aggregate.----Rangers won 2–0 on aggregate.
Unión Española won 5–1 on aggregate.----Huachipato won 2–1 on aggregate.
4–4 on aggregate. Huachipato won 3–2 on penalties.
| Teams | Scores | Tie-breakers | |||||
|---|---|---|---|---|---|---|---|
| Team #1 | Team #2 | 1st leg | 2nd leg | ||||
| Universidad de Concepción | 0:6 | Everton | 0–1 | 1–3 | - | - | |
| Cobresal | 3:3 | Barnechea | 1–3 | 3–0 | +1:−1 | - | |