The word(s) "oppressors" appears 2 time(s) in 2 verse(s) in Quran in Muhammad Pickthal translation.

(1) How should ye not fight for the cause of Allah and of the feeble among men and of the women and the children who are crying: Our Lord! Bring us forth from out this town of which the people are oppressors! Oh, give us from thy presence some protecting friend! Oh, give us from Thy presence some defender!

(سورة النساء, An-Nisaa, Chapter #4, Verse #75)
(Arabic, Transliteration, Urdu (Ahmed Ali), Urdu (Jalandhry), Farsi, Yusuf Ali, Shakir, Picthal, Mohsin Khan, French, Spanish, Indonesian, Malay, German, Bosnian, Russian, Dutch, Italian, Portuguese, Tafsir - Jalal ad-Din, Tafsir - King Fahad Quran Complex)

(2) For reminder, for We never were oppressors.

(سورة الشعراء, Ash-Shu'araa, Chapter #26, Verse #209)
(Arabic, Transliteration, Urdu (Ahmed Ali), Urdu (Jalandhry), Farsi, Yusuf Ali, Shakir, Picthal, Mohsin Khan, French, Spanish, Indonesian, Malay, German, Bosnian, Russian, Dutch, Italian, Portuguese, Tafsir - Jalal ad-Din, Tafsir - King Fahad Quran Complex)