A radical feminist is typically a follower of radical feminist philosophy. This philosophy usually states that women are oppressed physically, sexually, economically, and in other ways by men, and that these patterns of oppression spring from deep-seated patriarchal beliefs within many human cultures. Generally, a radical feminist believes that modern social and political systems tend to place men in positions of privilege and authority over women, and that many modern cultural and political constructs may therefore be flawed. Radical feminists generally believe that men and women are equals, and that the belief that men may be somehow superior to women probably springs from the perception that there are fundamental differences between the two genders. Most radical feminists wish to eradicate beliefs that women may be inferior to men, by changing the social and political systems that they believe foster misogynistic behavior.

The political philosophy referred to as radical feminism is considered to have its origins in the second-wave feminist movement of North America and Europe. Radical feminists are said to differ from liberal feminists in that they are perceived as more willing to actively agitate for social and political changes in line with their philosophy. Many believe that radical feminism is largely responsible for helping to equalize female roles in many Western societies in the decades since the second-wave feminist movement began in about 1960. Radical feminism is believed to be at least partially responsible for the tightening of laws to protect women from rape, domestic abuse, and other dangers believed rooted in sexism. It is also believed responsible for the increasing freedom of women in many Western societies since the second-wave feminist movement began.

The typical radical feminist probably believes that women have been oppressed by men throughout history, in almost all societies. Some radical feminists believe that the oppression of women by men is not only the oldest type of cultural oppression in existence, but also the most damaging to people, families, and communities. Acts of oppression attributed to misogynistic beliefs include rape, abuse, prostitution, and domestic abuse. Many radical feminists believe that they also include such constructs as rigidly defined gender roles that dictate dress and behavior for both men and women. Ideas that men and women are suited for different lifestyles, that women may be more fragile or more emotional than men, or that men may be stronger and more aggressive than women, are also believed to form part of the oppressive structure radical feminists typically rally against.

Not every radical feminist is a woman. The philosophy does not typically claim to exclude or punish men. Many radical feminists believe that men, too, are victims of sexist cultural ideas and political systems, and that they, too, suffer as a result of female oppression. Most radical feminists feel that the systemic oppression of women can only end when all members of society are able to perceive the genders as equal.