Brinkley was born in Atlanta, Georgia in 1960, but raised in Perrysburg, Ohio. His parents were high school teachers.

During the early 1990s, Brinkley taught American Arts and Politics for Hofstra aboard the Majic Bus, a roving transcontinental classroom, from which emerged the book The Majic Bus: An American Odyssey (1993). In 1993, he left Hofstra to teach at the University of New Orleans, where he taught the class again using two natural-gas fueled buses. According to the Associated Press, “…if you can’t tour the United States yourself, the next best thing is to go along with Douglas Brinkley aboard The Majic Bus.”

Brinkley’s first book was Jean Monnet: The Path to European Unity (1992). His second was Dean Acheson: The Cold War Years (1992). He then co-edited a monograph series with Arthur Schlesinger, Jr. and William vanden Heuvel in the 1990s. Brinkley also edited a volume on Dean Acheson and the Making of US Foreign Policy with Paul H. Nitze (1993). In 1999, he published The Unfinished Presidency about Jimmy Carter’s active and influential post-presidency.

In 2004, Brinkley released Tour of Duty: John Kerry and the Vietnam War, about U.S. Senator John Kerry’s military service and anti-war activism during the Vietnam War. The 2004 documentary movie, Going Upriver: The Long War of John Kerry is loosely based on Brinkley’s book. Brinkley also wrote the Atlantic Monthly cover story of December 2003 on Kerry.

Stephen Ambrose, Brinkley’s mentor at the University of New Orleans, called Brinkley “the best of the new generation of American historians.” Brinkley and Ambrose had co-authored three books. Patrick Reardon of the Chicago Tribune called Brinkley America’s “new past master.” In addition, during the 2013 inauguration coverage, CNN referred to him as “a man who knows more about the presidency than just about any human being alive.” In contrast, in 2006, historian Wilfred McClay in the New York Sun appraised Brinkley’s scholarship as one that has failed to “put forward a single memorable idea, a single original analysis, or a single lapidary phrase.” Similarly, author Bill Bryson characterized Brinkley as “a minor American academic and sometime critic whose powers of observation and generosity of spirit would fit comfortably into a proton and still leave room for an echo”.

On November 18, 2011, during his testimony before a Congressional hearing on drilling in the Arctic National Wildlife Refuge, Brinkley had a heated exchange with Rep. Don Young. Young, who had not been present during Brinkley’s testimony, nonetheless characterized it as “garbage” and addressed Brinkley as “Dr. Rice.” In response, Brinkley stated, “It’s Dr. Brinkley. Rice is a university. I know you went to Yuba College and couldn’t graduate.” Brinkley also noted that Young’s comments were made even though Young had not been present during his testimony.

Brinkley’s biography of Walter Cronkite, Cronkite was published in 2012. It was also selected as a Washington Post Book of the Year.