Jewish roots
A Jewish father: patrilineal descent
Halacha passes Jewish status through the mother, so when only your father is Jewish, your situation is handled differently, and a rabbi or beis din decides the path. That isn’t a closed door. Many men with a Jewish father go on to join the Jewish people fully, and a brit is often part of that.
Why it’s handled differently
In halacha, Jewish status passes through the mother, not the father. Some movements, such as Reform Judaism in North America, recognise patrilineal descent; Orthodox communities and most batei din do not. So the answer can depend on the community you hope to belong to, and it helps to know that early.
None of this says anything about how Jewish you feel, or about your father’s love for his heritage. It is simply how the question is answered in halacha.
What the path usually looks like
A rabbi gets to know you and your family. For a man with a Jewish father and a non-Jewish mother, the path is usually a conversion through a beis din. For a man, that includes a brit: brit milah if he was never circumcised, or hatafas dam bris if he was. The beis din sets the steps and the timing.
Look at your mother’s side too
Sometimes a mother or grandmother had Jewish roots that nobody talked about. If there is any chance of that, mention it. It can change the picture entirely. See a Jewish mother.
Where I fit in
I am a mohel, not a beis din, and I don’t decide anyone’s status. What I can do is listen, explain, help you find a rabbi if you don’t have one, and, when your rabbi or beis din asks for it, perform the brit and coordinate with them directly.
You can answer a few short questions about your family and I’ll call you back.
Ask, privately.
The first conversation costs nothing and commits you to nothing. More answers in the adult FAQ.