Her books include Wartime: Britain 1939-1945 (Headline, 2004) which recounts the history of the Home Front during World War II. Gardiner also wrote the books to accompany the Channel 4 television series The 1940s House (2000) and The Edwardian Country House (2002), and three books linked to exhibitions at London's Imperial War Museum, From the Bomb to the Beatles (1999), The Children's War: The Second World War Through the Eyes of the Children of Britain (2005) and The Animals' War: Animals in Wartime from the First World War to the Present Day (2006). Gardiner was also the editor of Who's Who in British History (2000, Collins & Brown), the "History Today" Companion to British History (1996, Collins & Brown) with Neil Wenborn and The Penguin Dictionary of British History (2000). She acted as historical consultant to the film of Atonement, and is a frequent broadcaster on radio and television, a reviewer and a contributor to the national press, including The Sunday Times, Sunday Telegraph, Financial Times, The Guardian and BBC History.
Gardiner's book on 1930s Britain, The Thirties: An Intimate History, was published by HarperCollins in 2009.[4] Its purpose was, as Gardiner herself has explained, to take the structure of the 1930s, formed over the years by political and economic historians, and "fill in as many details as possible" about how people lived their lives during that period.[5]
Gardiner's most recent[as of?] book:; The Blitz: The British Under Attack was published in 2010 by Harper Press (ISBN 978-0-007240777).
In 2012, Gardiner wrote and presented a series for BBC Radio 4 entitled The History of the Future a series of ten programmes exploring how cultures of the past viewed the possibilities of the future.[6]