Rachel Hannah Weisz was born in Westminster, London, to Edith Ruth (née Teich), a Vienna-born psychoanalyst, and George Weisz, a Hungarian-Jewish mechanical engineer. Her parents were refugees who fled to Britain before World War II.

Weisz grew up in Hampstead Garden Suburb, a well-to-do area of London. Her upbringing was culturally rich, with exposure to art, literature, and intellectual discourse, likely influencing her later career choices.

Weisz attended North London Collegiate School, an independent day school for girls known for its academic rigor. This likely contributed to her sharp intellect and later success in higher education.

Weisz completed her sixth form (final two years of secondary education) at St Paul's Girls' School, another prestigious independent school in London. This further cemented her academic foundation.

During her school years, Weisz formed the theatre company 'Talking Tongues' with Sasha Hails. They won the Guardian Student Drama Award at the Edinburgh Fringe Festival, showcasing Weisz's early talent and entrepreneurial spirit.

Weisz pursued a degree in English at Trinity Hall, Cambridge, a prestigious university. While studying, she continued to act in student productions, further honing her skills and solidifying her commitment to acting as a career.