Robert Murray Lyman (born 13 June 1963) is a British military historian. He has published a number of popular books on the Second World War.
Born in New Zealand, Lyman was educated at Scotch College, Melbourne and joined the British Army at the age of 18. He was commissioned into the Light Infantry from the Royal Military Academy Sandhurst in 1982 and left the army as a Major.
Following his career in the British Army, Lyman has published over 16 books on the Second World War in Europe, North Africa and Asia. He regularly appears on TV and radio and reviews books for newspapers and magazines. His presentation of the case for Field Marshal Sir William Slim won a National Army Museum debate in 2011 for Britain's Greatest General and his case for Kohima/Imphal won a National Army Museum debate in 2012 for Britain's Greatest Battle. Lyman regularly gives lectures at organisations such as the National Army Museum, and he is also a battlefield guide.
Lyman has been a trustee of the Kohima Educational Trust since 2004, and chairman between 2008 and 2016.
He is a fellow of the Royal Historical Society.
Lyman was appointed Member of the Order of the British Empire (MBE) in the 2024 New Year Honours for services to military history and charity work in Nagaland.