To increase blessings for yourself and your parents and instill gratitude, recite the following:
رَبِّ أَوْزِعْنِي أَنْ أَشْكُرَ نِعْمَتَكَ الَّتِي أَنْعَمْتَ عَلَيَّ وَعَلَىٰ وَالِدَيَّ وَأَنْ أَعْمَلَ صَالِحًا تَرْضَاهُ وَأَدْخِلْنِي بِرَحْمَتِكَ فِي عِبَادِكَ الصَّالِحِينَ
Transliteration: Rabbi awzi’nī an ashkura ni’matakal-latī an’amta ‘alayya wa ‘ala wālidayya wa an a’mala salihan tardhāhu wa adkhilnī birahmatika fī ‘ibādikas-soliheen
Translation: My Lord, inspire me to (always) be thankful for the blessings You have granted me and my parents, and to do good deeds that please You; admit me by Your grace into the ranks of Your righteous servants
Du’a for Deceased Parents
The following du’a can be recited for any loved one who has passed away, including your parents:
اللهُـمِّ اغْفِـرْ لَهُ وَارْحَمْـه ، وَعافِهِ وَاعْفُ عَنْـه ، وَأَكْـرِمْ نُزُلَـه ، وَوَسِّـعْ مُدْخَـلَه ، وَاغْسِلْـهُ بِالْمـاءِ وَالثَّـلْجِ وَالْبَـرَدْ ، وَنَقِّـهِ مِنَ الْخطـايا كَما نَـقّيْتَ الـثَّوْبَ الأَبْيَـضَ مِنَ الدَّنَـسْ ، وَأَبْـدِلْهُ داراً خَـيْراً مِنْ دارِه ، وَأَهْلاً خَـيْراً مِنْ أَهْلِـه ، وَزَوْجَـاً خَـيْراً مِنْ زَوْجِه ، وَأَدْخِـلْهُ الْجَـنَّة ، وَأَعِـذْهُ مِنْ عَذابِ القَـبْر [وَعَذابِ النّـار]
Transliteration: Allāhumma’ghfir lahu warḥamh, wa `āfihi, wa`fu `anh, wa akrim nuzulah, wa wassi` mudkhalah, wagh’silhu bi ‘lmā’i wath-thalji walbarad, wa naqqihi mina ‘l-khaṭāyā kamā naqqaytath-thawba ‘l-abyaḍa minad-danas, wa abdilhu dāran khayran min dārih, wa ahlan khayran min ahlih, wa zawjan khayran min zawjih, wa adkhilhu ‘l-jannah, wa a`idhhu min `adhābi ‘l-qabri [wa`adhābin-nār].
Note: For a male the ‘hu’ and ‘hi’ pronouns (in bold) have been used. For a female you can replace both these pronouns with ‘ha’.
Translation: O Allah, forgive him/her and have mercy on him/her, and give him/her strength and pardon him/her. Be generous to him/her, and cause his/her entrance to be wide, and wash him/her with water and snow and hail. Cleanse him/her of his/her transgressions as white cloth is cleansed of stains. Give him/her an abode better than his/her home, and a family better than his/her family, and a wife/husband better than his/her wife/husband. Take him/her into Paradise, and protect him/her from the punishment of the grave [and from the punishment of Hell-fire].
Du’a for forgiveness for parents
رَبَّنَا اغْفِرْ لِي وَلِوَالِدَيَّ وَلِلْمُؤْمِنِينَ يَوْمَ يَقُومُ الْحِسَابُ
Transliteration: Rabbana-ghfirlī wa liwālidayya wa lilmu’minīna yauma yaqūmul-hisāb
Translation: Our Lord! Forgive me, my parents, and the believers on the Day when the judgment will come to pass.
Du’a for mercy for parents
رَّبِّ ارْحَمْهُمَا كَمَا رَبَّيَانِي صَغِيرًا
Transliteration: Rabb-irhamhumā kamā rabbayānee sagheerā
Translation: My Lord! Be merciful to them as they raised me when I was young.