H. O. Arnold-Forster was a British author and politician whose books sought to explain history, citizenship, and public institutions to a broad readership. His educational works include A History of England and The Citizen Reader. Combining an interest in teaching with practical political experience, he wrote about the responsibilities of citizens and the organization of national life.

Educated at Rugby and Oxford, Hugh Oakeley Arnold-Forster trained as a barrister before pursuing publishing and politics. He joined Cassell and prepared educational manuals, bringing an accessible approach to subjects that could otherwise appear remote to young readers. His parliamentary career included representing West Belfast and Croydon, along with service in government.

As Secretary of State for War, he became closely involved in debates over military organization and reform. That concern also appears in books such as Our Home Army and Military Needs and Military Policy. His wider output includes geography and accounts of everyday law. Read in their historical setting, his books show how late Victorian and Edwardian educators connected knowledge of the past with ideas about citizenship, public service, and empire.