David H. Kranzler (May 19, 1930 – November 29, 2007)[1] was an American professor of library science at Queensborough Community College, New York, who specialized in the study of the rescue of Jews during the Holocaust.

[11] After working as a school librarian, Kranzler joined the faculty of Queensborough Community College (QCC) of the City University of New York in 1969, and was a professor in the library department until his retirement in 1988.

"[14] Kranzler's books Solomon Schonfeld: His Page in History, co-authored with Gertrude Hirschler, and his later Thy Brother's Blood (1987) were the first to focus on this area.

[17] In his book Thy Brother's Blood: The Orthodox Jewish Response During the Holocaust (1987), Kranzler argued that more lives could have been saved if American-Jewish leaders had lent more support to efforts in Europe to halt the deportations, including the attempts, in Slovakia and Hungary, to bribe and/or pay ransom to the SS.

[18] In the view of historian Robert Moses Shapiro, the book's defects, particularly its bitter tone and poor editing, undermined its "important and gripping story".

[19] The mid-1944 grassroots protests in Switzerland, including street demonstrations, Sunday sermons and the Swiss press campaign of about 400 headlines about the atrocities were triggered by George Mantello making public a summary of the Auschwitz Report (Vrba–Wetzler report) is the subject of Kranzler's book The Man Who Stopped the Trains to Auschwitz: George Mantello, El Salvador and Switzerland's Finest Hour (2000), which has a foreword by Joe Lieberman.