Do Jews believe that each person has a guardian angel watching over him or her?
Jews certainly believe in angels – spiritual entities who exist to perform the will of G‑d (the Hebrew word for angel, "malach," also means "messenger") – the Scriptures contain many references to such supernal beings. But the popular idea of private and personal guardian angels is not part of Jewish theology.
Instead, we believe in a personal G‑d who constantly watches over each and every one of us, and over all of creation. On occasion He may send an angel to help or save us, but the angel is merely His emissary.
However, our sages tell us that each mitzvah that we do creates an angel that serves as a shield and protection for us. After our passing, these angels testify on our behalf before the Heavenly Courts.
So in that sense, we create our own guardian angels.
I hope this has been helpful.
Chaya Sarah Silberberg,