Is it halal for someone to call himself ‘The Master’, as a nickname on the internet and websites, especially if one does not do that out of arrogance but just to make clear that he has an influence on that website or app? If it is not halal, then what about using the nickname ‘The Mister’? Thank you.

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah and that Muhammad, sallallahu ‘alayhi wa sallam, is His slave and Messenger. 

The scholarly view adopted at Islamweb is that it is permissible to use the title “As-Sayyid” (The Master) in reference to the Muslim individual. Ibn Al-Qayyim wrote:

“Scholars held different views regarding the permissibility of using ‘As-Sayyid (The Master)’ in reference to people; some maintained that it is prohibited and argued that when people said to the Prophet, sallallahu ‘alayhi wa sallam, ‘O our master...’ he said, ‘The Master is Allah.’ (Saheeh [sound]) Others held that it is permissible and relied on the hadeeth in which the Prophet, sallallahu ‘alayhi wa sallam, said to the Ansaar, ‘Stand up, showing respect to your master (i.e. Saa'd ibn Mu'aath).’ This hadeeth is more authentic than the first hadeeth ... When the word As-Sayyid (The Master) is used in reference to Allah, it means ‘The Owner, The Sovereign, The Lord’ which is different from the intended meaning when it is used in reference to humans.” [Badaa'i’ Al-Fawaa'id]

Hence, there is no harm in using the word ‘The Mister’ or ‘The Master’ especially if it is used to identify the person who is responsible for the website or the like. Muslim scholars underlined that the prohibition of using the word The Master in reference to anyone other than Allah is when it is used for glorification and not for the purpose of identification. Al-Munaawi wrote, “The word ‘The Master’ with the definite article is commonly used in the Quran and Sunnah in reference to other than Allah. An-Nawawi  said, 'What is prohibited is to use the word ‘The Master’ for the purpose of glorification, not for the purpose of identification...'” [Faydh Al-Qadeer]

Allah knows best.