Dua for Istikhara (seeking guidance)
اللّهُـمَّ إِنِّـي أَسْتَخيـرُكَ بِعِلْـمِك، وَأَسْتَقْـدِرُكَ بِقُـدْرَتِـك،...
اللّهُـمَّ إِنِّـي أَسْتَخيـرُكَ بِعِلْـمِك، وَأَسْتَقْـدِرُكَ بِقُـدْرَتِـك، وَأَسْـأَلُـكَ مِنْ فَضْـلِكَ العَظـيم، فَإِنَّـكَ تَقْـدِرُ وَلا أَقْـدِر، وَتَـعْلَـمُ وَلا أَعْلَـم، وَأَنْـتَ عَلاّمُ الغُـيوب، اللّهُـمَّ إِنْ كُنْـتَ تَعْـلَمُ أَنَّ هـذا الأمْـرَ خَـيْرٌ لي في دينـي وَمَعـاشي وَعاقِـبَةِ أَمْـري فَاقْـدُرْهُ لي وَيَسِّـرْهُ لي ثُـمَّ بارِكْ لي فيـه، وَإِنْ كُنْـتَ تَعْـلَمُ أَنَّ هـذا الأمْـرَ شَـرٌّ لي في دينـي وَمَعـاشي وَعاقِـبَةِ أَمْـري فَاصْرِفْـهُ عَنِّـي وَاصْرِفْني عَنْـهُ وَاقْـدُرْ لي الخَـيْرَ حَيْـثُ كانَ ثُـمَّ أَرْضِـني بِـه
Allahumma innee astakheeruka biAAilmik, wa-astaqdiruka biqudratik, wa-as-aluka min fadlikal-AAatheem, fa-innaka taqdiru wala aqdir, wataAAlamu wala aAAlam, wa-anta AAallamul-ghuyoob, allahumma in kunta taAAlamu anna hathal-amra khayrun lee fee deenee wamaAAashee waAAaqibati amree faqdurhu lee, wayassirhu lee, thumma barik lee feeh, wa-in kunta taAAlamu anna hathal-amra sharrun lee fee deenee wamaAAashee waAAaqibati amree fasrifhu AAannee wasrifnee AAanh, waqdur liyal-khayra haythu kan, thumma ardinee bih
Translation
O Allah, I seek Your counsel by Your knowledge and by Your power I seek strength and I ask You from Your immense favour, for verily You are able while I am not and verily You know while I do not and You are the Knower of the unseen. O Allah, if You know this affair to be good for me in relation to my religion, my life, and end, then decree and facilitate it for me, and bless me with it, and if You know this affair to be ill for me towards my religion, my life, and end, then remove it from me and remove me from it, and decree for me what is good wherever it be and make me satisfied with such.
When to recite
Recited after two rakah of voluntary prayer when seeking guidance on any matter. Mention your need where it says "this affair".
Source / Reference
Al-Bukhari 7/162