 Wanstall was born at Brisbane, Queensland, the son of Ernest William Wanstall and his wife Emma (née Boyce).He attended state school in Roma and Gympie and then the Gympie High School (Secondary Education – Junior Certificate).He attended night school and studied Law with the Bar Board (Formal Education – Barristers Board Queensland) to become a Barrister (Barrister-at-Law) and having completed the Bar Board requirements in 1933 and was admitted as a Barrister of the Supreme Court of Queensland.