O Allah, forgive our deceased and the deceased of the Muslims. — Death & Funerals
اللَّهُمَّ اغْفِرْ لِأَمْوَاتِنَا وَأَمْوَاتِ الْمُسْلِمِينَ
Transliteration: Allaahummagh-fir li-amwaatinaa wa amwaatil-muslimeen
Translation: O Allah, forgive our deceased and the deceased of the Muslims.
Reference: General supplication