Alyson Hannigan was born in Washington, D.C, but grew up in Atlanta, Georgia with her mother after her parents’ divorce. Hannigan’s father is of Irish descent, 1 shows what may be partly Catholic. Her mother was a Jew, the grandson of Russian Jewish immigrants.2 And given that she was raised with her mother, it would make sense that she would identify more as a Jew.
Hannigan was raised by a Jewish mother and her father was rooted in Catholicism, but she did not seem to be entirely religious.
Hannigan has shown some enthusiasm for Obama, and her character is often willing to push the boundaries of sexual conventions. Some evidence suggests she was a liberal Democrat – or something like that.