Kathleen Helen Summersby BEM (née MacCarthy-Morrogh; 23 November 1908 – 20 January 1975), known as Kay Summersby, was a member of the British Mechanised Transport Corps during World War II, who served as a chauffeur and later as personal secretary to Dwight D. Eisenhower during his period as Supreme Commander Allied Expeditionary Force in command of the Allied forces in north west Europe.

As a young woman, she moved to London where she worked as a film studio extra, dabbled in photography, and eventually became a fashion model.

There was an engagement to marry US Army officer Lieutenant Colonel Richard "Dick" Arnold that overlapped her initial period with Eisenhower; however, this ended with the death of her fiancé while mine clearing during the North Africa campaign.

[6][7] When Britain entered World War II in 1939, Kay Summersby joined the British Mechanised Transport Corps (MTC).

[7] When the United States joined the Allies after the German declaration of war in December 1941, Summersby was one of many MTC drivers assigned as chauffeurs to high-ranking American military officers.

[10] After leaving the service in 1947, Summersby settled in the United States, and was, at one point, engaged to a man in San Francisco who thought she had money.

In Eisenhower Was My Boss, Summersby's 1948 memoir of the war years, written with journalist Frank Kearns, she made no mention of any affair.

[15] Instead of sex, wrote Summersby, the affair mostly consisted of "stolen kisses" during walks or on aeroplanes, holding hands, and horseback riding or golfing together.

[7] Historian Carlo D'Este notes that members of Eisenhower's staff denied that there was ever an affair between them and dismisses Summersby's book as "fanciful".

"[7] Field Marshal Bernard Law Montgomery wrote in his diary that Past Forgetting "should have never been written, it can do Eisenhower no good.

If American generals were in the habit of dealing with women secretaries and drivers as Eisenhower did and others appear to have done if this book is true, then their characters slump in the eyes of the world.

Smith accepted Miller's account because Garrett Mattingly, who as a naval officer in Washington censored outgoing cables, told a similar story to his Columbia University faculty colleagues in the early 1950s.

Omar Bradley in his autobiography wrote that the two were in love and that "Their close relationship is quite accurately portrayed, so far as my personal knowledge extends, in Kay's second book, Past Forgetting".