The author of the influential feminist book "The Feminine Mystique" is Betty Friedan. Published in 1963, Friedan's work challenged traditional gender roles and articulated the dissatisfaction many women felt in their suburban domestic lives. Her insights became a rallying cry for the second wave of feminism in the United States, helping to catalyze social change and promote gender equality. Friedan's contributions to the feminist movement have significantly shaped contemporary discussions on women’s rights and societal expectations.