A gender role, or sex role, is a social norm deemed appropriate or desirable for individuals based on their gender or sex, and is usually centered on societal views of masculinity and femininity.

The specifics regarding these gendered expectations may vary among cultures, while other characteristics may be common throughout a range of cultures. In addition, gender roles (and perceived gender roles) vary based on a person's race or ethnicity.

Gender roles influence a wide range of human behavior, often including the clothing a person chooses to wear, the profession a person pursues, manner of approach to things, the personal relationships a person enters, and how they behave within those relationships. Although gender roles have evolved and expanded, they traditionally keep women in the "private" sphere, and men in the "public" sphere.

Various groups, most notably feminist movements, have led efforts to change aspects of prevailing gender roles that they believe are oppressive, inaccurate, and sexist.

A gender role, also known as a sex role, is a social role encompassing a range of behaviors and attitudes that are generally considered acceptable, appropriate, or desirable for a person based on that person's sex. Gender roles can be linked with essentialism, the idea that humans have a set of attributes that are necessary to their identity based on their gender. Sociologists tend to use the term "gender role" instead of "sex role", because the sociocultural understanding of gender is distinguished from biological conceptions of sex.

In the sociology of gender, the process whereby an individual learns and acquires a gender role in society is termed gender socialization.

Gender roles are culturally specific, and while most cultures distinguish only two (boy/man and girl/woman), others recognize more. Some non-Western societies have three genders: men, women, and a third gender. Buginese society has identified five genders. Androgyny has sometimes also been proposed as a third gender. An androgyne or androgynous person is someone with qualities pertaining to both the male and female gender. Some individuals identify with no gender at all.

Many transgender people identify simply as men or women, and do not constitute a separate third gender. Biological differences between (some) trans women and cisgender women have historically been treated as relevant in certain contexts, especially those where biological traits may yield an unfair advantage, such as sport.