In 1995, Hamilton appeared in Ibsen's The Master Builder directed by Peter Hall, starring Alan Bates and Gemma Jones and performed at the Haymarket Theatre in the West End of London. The Independent described Hamilton as a "formidable talent" despite being a newcomer, and noted that she had previously appeared in two performances held at the Orange Tree Theatre in London, one of them being an adaptation of a play by James Saunders. The Master Builder earned Hamilton the London Critics Circle Theatre Award for Most Promising Newcomer. In 2000 she received the Critics' Circle Theatre Award for her performance in As You Like It, Crucible Theatre.