This I Believe: The Personal Philosophies of Remarkable Men and Women is a collection of eighty essays which explore the faiths, beliefs, and personal motivations of their American contributors, from the famous to the unknown. The collection was edited by Jay Allison and Dan Gediman and was published in 2007.

The name of the book was taken from "This I Believe," a five-minute radio program hosted by journalist Edward R. Murrow, which aired on CBS Radio Network from 1951 to 1955. The show was relaunched by Allison and Gediman on National Public Radio in 2005. "This I Believe" encouraged guests to write short essays about their personal faith, the evolution of that faith, and the belief systems they use to guide them through their everyday lives. They would then read their essays live on air. The show included guests from all walks of life, although the 1950s show did focus more on celebrities than the 2005 relaunch.

This I Believe: The Personal Philosophies of Remarkable Men and Women features eighty essays and includes contributions from both periods of the show. Famous essayists include Eleanor Roosevelt, Colin Powell, Leonard Bernstein, William F. Buckley Jr., Albert Einstein, Bill Gates, Oscar Hammerstein II, and Helen Keller. Unknown essayists include a Brooklyn lawyer; a part-time hospital clerk in Rehoboth, Massachusetts; a woman who sells yellow pages advertising in Fort Worth, Texas; an English professor; and a man who serves on Rhode Island's parole board.

In the introduction, Jay Allison discusses the hypothesis for and the history of the radio show, and he also explains the premise of the book. In the foreword, Studs Terkel considers how the original objective of the show is still relevant today. And, in the afterword, Dan Gediman reviews the contributions and their contributors.