1A polite/respectful way to refer to one's father (or someone else's), commonly used in conversation.
お父さん、今日は早く帰ってきてくれてありがとう。
Dad, thank you for coming home early today.
明日、お父さんに仕事のことで相談します。
I'll consult my father about work tomorrow.
お父さんは釣りが好きで、毎週末出かける。
My dad likes fishing and goes out every weekend.
お父さんの誕生日には家族みんなでケーキを作った。
For Dad's birthday, the whole family made a cake together.
2Also used by a wife to address or refer to her own husband, as an extension of the parental address term.
結婚してから、彼女は夫のことを名前ではなく「お父さん」と呼ぶようになった。
Since getting married, she started calling her husband "Dad" instead of using his name.
近所の奥さんは、旦那さんのことをいつも「お父さん」と呼んでいる。
The wife next door always calls her husband "Dad."
3In familiar or colloquial speech, used to address or refer to an older man, similar to "you" or "he" — a dialectal, less common usage.
お父さん、そこの荷物落ちてますよ。
Excuse me, sir, you dropped something over there.
あそこにいるお父さん、毎朝ここを散歩してるんだよ。
That old man over there walks here every morning.