Barbara Joan Branden (née Weidman; May 14, 1929 – December 11, 2013) was a Canadian-American writer, editor, and lecturer, known for her relationship and subsequent break with novelist-philosopher Ayn Rand.

[1][2][3][4] Born in Winnipeg, Barbara Weidman met Nathaniel Branden because of their mutual interest in Ayn Rand's works.

She served as the executive director of the Nathaniel Branden Institute, and gave a series of lectures on "Principles of Efficient Thinking."

[13] Rand had previously claimed that the friendship broke up over other matters, but letters in her estate confirmed Barbara Branden's version of the cause.

[13] The book was made into an Emmy Award-winning motion picture in 1999 starring Helen Mirren as Rand, Eric Stoltz as Branden and Julie Delpy playing Barbara.