Doubleday may refer to:

• Doubleday (surname), including a list of people with the name

• Doubleday (publisher), imprint of Knopf Doubleday, a subsidiary of Penguin Random House
• Doubleday Canada, imprint of Penguin Random House Canada
• Image, formerly Doubleday Religion, imprint of Crown Publishing Group, a subsidiary of Penguin Random House

• Doubleday Field, Cooperstown, New York, USA; baseball stadium
• Doubleday Field, United States Military Academy, West Point, New York State, USA; a region of the academy; see Johnson Stadium at Doubleday Field
• Auburn Doubledays, single-A baseball team, from Auburn, New York State, USA

• SS Abner Doubleday, Liberty ship built during World War II
• Henry Doubleday Research Association, UK organic growing charity

• All pages with titles beginning with Doubleday
• All pages with titles containing Doubleday
• Doubleday myth about the creation of baseball by Abner Doubleday