Is There Any Du’a For Guidance of Someone You Love?
Question

Is there a du’a (supplication) for a person whom we love to be guided?
Praise be to Allah.Is there any du’a for guidance?
Yes, there are many du’as which we may say for those whom we love and those whom we do not love to be guided. We can say: O Allah guide him; O Allah, make him guided and a guide to others; O Allah, open his heart to the truth; O Allah, help and guide him; O Allah, take him by the forelock and guide him to righteousness and piety; O Allah, bring him back to You; and so on. 
Du’as for guidance from the Sunnah
Du’as for guidance that have been narrated in the sunnah (prophetic teachings) include the following: 

Al-Bukhari and Muslim narrated that Abu Hurayrah (may Allah be pleased with him) said: Tufayl ibn ‘Amr al-Dawsi came to the Prophet (peace and blessings of Allah be upon him) and said: “Daws (a well-known tribe) are doomed, they have disobeyed and been stubborn. Pray to Allah against them.” He said: “O Allah, guide Daws and bring them here.” 
Muslim narrated that Abu Hurayrah (may Allah be pleased with him) said: I used to call my mother to Islam when she was still a mushrik (polytheist). I called her one day and she said something about the Messenger of Allah (peace and blessings of Allah be upon him) that I did not like to hear. I came to the Messenger of Allah (peace and blessings of Allah be upon him) weeping, and said, ‘O Messenger of Allah, I have been calling my mother to Islam and she refuses. I called her today and she said something about you that I did not like to hear. Pray to Allah to guide the mother of Abu Hurayrah.’ The Messenger of Allah (peace and blessings of Allah be upon him) said, ‘O Allah, guide the mother of Abu Hurayrah.’ I went back, feeling optimistic because of the du’a of the Messenger of Allah (peace and blessings of Allah be upon him). When I came back, I went to the door and found it locked. My mother heard my footsteps and said, ‘Stay where you are, O Abu Hurayrah.’ I could hear the sound of water. She washed herself (did ghusl), put on her chemise and quickly covered her head with her head cover, then she opened the door and said, ‘O Abu Hurayrah, I bear witness that there is no god except Allah, and I bear witness that Muhammad is His slave and Messenger.’ I went back to the Messenger of Allah (peace and blessings of Allah be upon him), weeping with joy, and said, ‘O Messenger of Allah, good news! Allah has answered your prayer and guided the mother of Abu Hurayrah.’ He praised and thanked Allah.” 
Al-Bukhari and Muslim narrated that Jarir (may Allah be pleased with him) said: The Prophet (peace and blessings of Allah be upon him) did not refuse me permission to enter (upon him in his house) since I became Muslim, and whenever he saw me he smiled at me. I complained to him that I could not sit firmly when riding a horse and he struck me on the chest with his hand and said, “O Allah, guide him and make him a guide to others.” 

Best times for having your du’a answered
The du’a should be accompanied with certain faith in a response, and you should choose the times when a response is more likely , such as the last third of the night, between the adhan (call to prayer) and iqamah (final call to prayer), whilst prostrating, and after ‘Asr (afternoon prayer) on Friday, as well as seeking to ensure that one’s income and food are halal (lawful), and other etiquettes of du’a. Please see the answer to question no. 36902 .
And Allah knows best.