| Date: | 24–30 September |
| Edition: | 4th |
| Category: | World Tour 250 |
| Draw: | 28S / 16D |
| Prize Money: | $850,000 |
| Surface: | Hard |
| Location: | Kuala Lumpur, Malaysia |
| Champs: |  Juan Mónaco |
| Champd: |  Alexander Peya /  Bruno Soares |
The 2012 Proton Malaysian Open was a professional men's tennis tournament played on hard courts. It was the fourth edition of the tournament, and part of the 2012 ATP World Tour. It took place in Kuala Lumpur, Malaysia between 24 and 30 September 2012. Juan Mónaco won the singles title.
| Country | Player | Rank1 | Seed | |
|---|---|---|---|---|
 Spain | David Ferrer | 5 | 1 | |
| Argentina | Juan Mónaco | 11 | 2 | |
 Japan | Kei Nishikori | 17 | 3 | |
 Ukraine | Alexandr Dolgopolov | 19 | 4 | |
| Spain | Feliciano López | 32 | 5 | |
| Spain | Pablo Andújar | 33 | 6 | |
 France | Julien Benneteau | 34 | 7 | |
| Austria | Jürgen Melzer | 37 | 8 |
The following players received wildcards into the singles main draw:
The following players received entry from the qualifying draw:
The following player received entry as lucky loser:
Marcos Baghdatis
Santiago Giraldo
Martin Kližan (oblique muscle injury)
Sam Querrey
Andreas Seppi (fatigue)
Nikolay Davydenko Jürgen Melzer (left quadriceps injury)| Country | Player | Country | Player | Rank1 | Seed | |
|---|---|---|---|---|---|---|
 Poland | Mariusz Fyrstenberg | Poland | Marcin Matkowski | 21 | 1 | |
| Italy | Daniele Bracciali | Brazil | Marcelo Melo | 45 | 2 | |
| Austria | Alexander Peya | Brazil | Bruno Soares | 56 | 3 | |
| Austria | Julian Knowle | Slovakia | Filip Polášek | 59 | 4 |
The following pairs received wildcards into the doubles main draw:
The following pair received entry as alternates:
Jürgen Melzer (left quadriceps injury) Martin Kližan (oblique muscle injury)See main article: 2012 Proton Malaysian Open – Singles.
Juan Mónaco defeated Julien Benneteau 7–5, 4–6, 6–3[1]See main article: 2012 Proton Malaysian Open – Doubles.
Alexander Peya / Bruno Soares defeated 
Colin Fleming / Ross Hutchins, 5–7, 7–5, [10–7]
