Windeyer was born in Sydney, into
a legal family: his father, William Archibald Windeyer (1871–1943) was a Sydney solicitor, his uncle,
Richard Windeyer, was a
King's Counsel, his grandfather,
William Charles Windeyer, was twice
Attorney-General of New South Wales and Judge of the
Supreme Court of New South Wales, and his great-grandfather, Sir
Richard Windeyer, was a
barrister and member of the first elected
Parliament of New South Wales, sitting in the
New South Wales Legislative Council. Windeyer studied at
Sydney Grammar School and later at the
University of Sydney, graduating with a Bachelor of Arts in 1922 (winning the university medal in history) and a Bachelor of Laws (LLB) in 1925. In 1925, Windeyer was admitted to the
New South Wales Bar Association. From 1929 to 1940, he lectured at the University of Sydney, teaching
equity and
commercial law, and until 1936, legal history. His book
Essays in Legal History published in 1938 was for many years a standard textbook on the subject. In 1939, Windeyer assisted
Justice Victor Maxwell at the
Australian Government Royal Commission into the extension of Sydney GPO. Windeyer married Margaret and they had four children Margaret, Bill, Jim and Frank. In 1938, he built a home called Peroomba in
Warrawee which only passed out of family ownership in 2008. ==Military career==