اللَّهُمَّ إِنِّي أَعُوذُ بِكَ مِنْ شَرِّ مَا عَمِلْتُ وَمِنْ شَرِّ مَا لَمْ أَعْمَلْ
Allahumma inni a'udhu bika min sharri ma 'amiltu wa min sharri ma lam a'mal
O Allah, I seek refuge in You from the evil of what I have done and from the evil of what I have not done.
Protection from two directions: the consequences of what you did (sins committed, hurtful words spoken, bad decisions made) and the consequences of what you didn't do (prayers missed, people not helped, opportunities for good wasted). Omission can be as dangerous as commission. This du'a covers both the sins of action and the sins of inaction.
Related Du'as
أُعِيذُكُمَا بِكَلِمَاتِ اللَّهِ التَّامَّةِ مِنْ كُلِّ شَيْطَانٍ وَهَامَّةٍ وَمِنْ كُلِّ عَيْنٍ لَامَّةٍ
I seek refuge for you both in the perfect words of Allah, from every devil, every venomous creature, and every envious evil eye.
Sahihاللَّهُمَّ إِنَّا نَجْعَلُكَ فِي نُحُورِهِمْ وَنَعُوذُ بِكَ مِنْ شُرُورِهِمْ
O Allah, we place You before them (as our shield) and we seek refuge in You from their evil.
Sahihاللَّهُمَّ إِنِّي أَعُوذُ بِرِضَاكَ مِنْ سَخَطِكَ وَبِمُعَافَاتِكَ مِنْ عُقُوبَتِكَ وَأَعُوذُ بِكَ مِنْكَ لَا أُحْصِي ثَنَاءً عَلَيْكَ أَنْتَ كَمَا أَثْنَيْتَ عَلَى نَفْسِكَ
O Allah, I seek refuge in Your pleasure from Your anger, in Your forgiveness from Your punishment, and I seek refuge in You from You. I cannot count Your praises. You are as You have praised Yourself.
Sahihأَعُوذُ بِكَلِمَاتِ اللَّهِ التَّامَّاتِ مِنْ شَرِّ مَا خَلَقَ
I seek refuge in the perfect words of Allah from the evil of what He has created.
Sahih