Alice Hastings Bradley was born on August 24, 1915, in Chicago, Illinois. She grew up in a family that valued education and culture. Her father, Herbert Edwin Bradley, was a lawyer and naturalist, while her mother, Mary Hastings Bradley, was a writer of fiction and travel books. Alice's early life was filled with travel. Her family often visited places like Africa and India.

In 1921 and 1922, the family took a trip to central Africa. During these adventures, young Alice was described as a well-behaved child who was always neatly dressed. Her mother's travels inspired Alice's later writing, particularly her story "The Women Men Don't See." Alice also appeared as the title character in two of her mother's travel books for children, called "Alice in Jungleland" and "Alice in Elephantland."

Alice received her education in Chicago. At age ten, she attended the University of Chicago Laboratory Schools, which had small class sizes and a unique teaching approach. When she was fourteen, she went to finishing school in Lausanne, Switzerland. After that, she returned to the U.S. for boarding school in Tarrytown, New York.

Alice's family encouraged her to have a career, yet her mother also wished for her to marry. In 1934, at the age of nineteen, Alice eloped with William "Bill" Davey. They moved to Berkeley, California, where they both took classes. However, their marriage was troubled, and they divorced in 1940. After the divorce, Alice worked as an art critic for the Chicago Sun newspaper and contributed to various art exhibitions.

In 1942, Alice joined the Women's Army Auxiliary Corps, where she served as a supply officer. She was later transferred to the U.S. Army Air Forces and became an intelligence officer. She worked in photo intelligence during World War II and achieved the rank of major. While stationed in Paris at the war's end, Alice met Huntington "Ting" Sheldon, an officer she eventually married in 1945.

After her service, Alice shifted her focus. In 1952, she and her husband were recruited by the CIA, where she worked as an intelligence officer until she resigned in 1955. Following her time at the CIA, Alice returned to school, earning a bachelor's degree at American University and later a PhD in Experimental Psychology from George Washington University in 1967. During these years, she began writing science fiction stories under the pseudonym James Tiptree Jr. in order to separate her writing from her academic reputation.

Alice Bradley Sheldon, who is also known by her pen name James Tiptree Jr., died on May 19, 1987, in a tragic event. In her final moments, Alice shot her husband, Huntington D. Sheldon, and then took her own life. This act followed years of struggle with depression and health issues.

Alice had expressed her feelings about her life and the possibility of ending it in letters to friends. In 1976, she noted that she didn't want to leave her husband behind, as he was also dealing with health problems. Eventually, she and her husband discussed making a suicide pact.

On the day of their deaths, Alice communicated with her attorney after shooting her husband, indicating her intentions. They were later found together in their home, which raised questions about the nature of their deaths. Some people believed it was a suicide pact, while others wondered if they might have been a murder-suicide, considering Huntington's possible unwillingness to end his life.

According to her biographer, Alice wrote a suicide note in 1979 and saved it for when it would be needed.