surrogate father
Noun
Meaning
A man who takes care of a child when one or more of the parents are unavailable (see also surrogate parent, foster parents).
A man who acts as a father figure to a child usually when a father is not in the picture.
Source: en.wiktionary.orgExamples
I don't run democracy. I train troops to defend democracy and I happen to be their surrogate father and mother as well as their commanding general.
Oscar Hammerstein was a surrogate father during all those many days, and weeks and months when I didn't see my own father.