Joseph P. Lash (December 2, 1909 - August 22, 1987) was an American radical political activist, journalist, and author. A close friend of Eleanor Roosevelt, Lash won the Pulitzer Prize for Biography and the National Book Award in 1972 for Eleanor and Franklin, the first of two volumes he wrote about the former First Lady.

Eleanor and Franklin is one of the most highly acclaimed biographies written in recent times. Its author, Joseph Lash, won the Pulitzer and National Book Award in biography, as well as the Francis Parkman Prize of the Society of American Historians. Its focus is Eleanor Roosevelt and her complex relationship with FDR. Based on her personal papers and ranging from her birth in 1884 to the death of her husband in 1945, this fascinating study reveals new dimensions in a marriage that had a significant impact on the course of American history.

Written with great insight and sensitivity by an author who was a close friend of Mrs. Roosevelt's for over twenty years, the volume explores the personal, familial and social influences that shaped Eleanor and prepared her for role as first lady and chief counselor to the president. In many ways Eleanor was her husband's conscience. Her idealism dictated the terms of the complex partnership she evolved with her husband during his rise through local and national politics.