Who Stole Feminism? How Women Have Betrayed Women is a 1994 book about American feminism by Christina Hoff Sommers, a writer who was at that time a philosophy professor at Clark University. Sommers argues that there is a split between equity feminism and what she terms "gender feminism". Sommers contends that equity feminists seek equal legal rights for women and men, while gender feminists seek to counteract historical inequalities based on gender. Sommers argues that gender feminists have made false claims about issues such as anorexia and domestic battery and exerted a harmful influence on American college campuses. Who Stole Feminism? received wide attention for its attack on American feminism, and it was given highly polarized reviews divided between conservative and liberal commentators. Some reviewers praised the book, while others found it flawed.

Sommers argues that, "American feminism is currently dominated by a group of women who seek to persuade the public that American women are not the free creatures we think we are." She refers to the ideology of feminists who believe that "our society is best described as a patriarchy, a 'male hegemony,' a 'sex/gender system' in which the dominant gender works to keep women cowering and submissive", as "gender feminism." She identifies herself with "equity feminism," based on belief in fair treatment for everyone. She criticizes feminist authors such as Naomi Wolf and Gloria Steinem, writing that in The Beauty Myth (1990), Wolf falsely claims that in the United States 150,000 women die of anorexia each year, a claim repeated by Steinem. According to Sommers, while "most experts are reluctant to give exact figures," the actual figure is likely to be somewhere between 100 and 400 deaths per year. Sommers criticizes Sheila Kuehl, Laura Flanders of Fairness and Accuracy in Reporting, and other writers and activists, for helping to popularize the claim that "incidence of domestic battery tended to rise by 40 percent" on Super Bowl Sunday, writing that the claim, widely reported by the American media, was unsupported by any study. Sommers argues that feminists have falsely accused the English legal historian William Blackstone of supporting a man's right to beat his wife. She writes that British law has prohibited wife beating since the 1700s, and American law has done the same since before the American Revolution, though the laws were sometimes only "indifferently enforced."

According to Sommers, many feminist theorists and researchers have dealt with male critics by calling them "sexist" or "reactionary", and female critics by calling them "traitors" or "collaborators", and that such tactics have "alienated and silenced women and men alike." In her view, gender feminism began to develop in the middle of the 1960s, due to "the antiwar and antigovernment mood" and the influence of thinkers such as Karl Marx, Jean-Paul Sartre, Herbert Marcuse, and Frantz Fanon. Sommers writes that Kate Millett's Sexual Politics (1969) "was critical in moving feminism in this new direction", teaching women that politics is "essentially sexual" and that "even the so-called democracies" are "male hegemonies." Sommers points to philosopher Michel Foucault and his Discipline and Punish (1975) as influences on Wolf and Susan Faludi, author of Backlash: The Undeclared War Against American Women (1991). She argues that Foucault's work is overrated. Discussing the influence of feminists on college campuses, she writes that in many cases feminist "consciousness-raisers are driving out the scholars." She adds that, "The gender feminists have proved very adroit in getting financial support from governmental and private sources" and "hold the keys to many bureaucratic fiefdoms, research centers, women's studies programs, tenure committees, and para-academic organizations. It is now virtually impossible to be appointed to high administrative office in any university system without having passed muster with the gender feminist."

Sommers expresses a favorable view of writers like the philosopher Janet Radcliffe Richards, author of The Sceptical Feminist (1980), Katie Roiphe, author of The Morning After (1993), whom Sommers defends against criticism from Katha Pollitt, and the critic Camille Paglia. Sommers argues that Paglia's Sexual Personae (1990) should have led to her being "acknowledged as an outstanding woman scholar even by those who take strong exception to her unfashionable views," and criticizes the Women's Review of Books for calling the book a work of "crackpot extremism" and feminist professors at Connecticut College for comparing it to the German dictator Adolf Hitler's Mein Kampf (1925).

Who Stole Feminism? was first reviewed in Kirkus Reviews in April 1994, two months prior to publication. The staff at Kirkus said that Sommers' book highlighted instances of "shoddy" research in feminist studies but failed to tell the reader about similar poor quality research in other fields. Sommers was said to be confused about categories of feminism, to have invented a sort of "gender feminism" to fit her purpose of promoting her brand of liberal feminism, and to have created "a theory of conspiracy equal in force to those she seeks to debunk." Kirkus said that Sommers presumed to speak for the majority of feminists "without providing persuasive evidence that most women are liberal feminists." Sommers was praised for her valid challenges to feminist ideology, but her assumptions were described as flawed.

Literary theorist Nina Auerbach reviewed the book for The New York Times Book Review in June 1994. She described Sommers' reasoning as being "vitiated by its logical flaws" and said that the John M. Olin Foundation, which paid for the book's publication, should have found "a less muddled writer" for the task. Sommers responded to the criticism by saying that the Times should not have assigned Auerbach to the review, since, as an organizer of a feminist event portrayed negatively in the book, she was sure to be prejudiced against the ideas in the book. Conservatives such as Jim Sleeper, Howard Kurtz and Rush Limbaugh defended Sommers; Limbaugh said that the Times was attempting to "kill this book." The feminist columnist Katha Pollitt, however, thought Auerbach's review was too polite and failed to give Sommers' book "the pasting it deserved."

Editor Deirdre English writing in The Washington Post Book World was appreciative of the investigative aspect of Sommers' work, but she questioned the polarized depiction of feminism. Calling Sommers a "well-published conservative [who] is itching for a fight," she said the book would likely provoke debate "as well as some retractions." English said of the book that "the root question is whether women want equality with men as they are, in the world men have shaped, or if women seek change in that world."

The book was positively reviewed by Cathy Young who was an executive colleague of Sommers in the Women's Freedom Network. It was also highly praised in the National Review by Sommers' close friend Mary Lefkowitz. Paglia called the book a "landmark study... which uses ingenious detective work to unmask the shocking fraud and propaganda of establishment feminism and the servility of American media and academe to Machiavellian feminist manipulation," adding that, "Sommers has done a great service for women and for feminism, whose fundamental principles she has clarified and strengthened." Melanie Kirkpatrick, writing in The Wall Street Journal, gave the book high marks, saying that "Sommers simply lines up her facts and shoots one bull's-eye after another."