Street harassment is a form of harassment, primarily sexual harassment that consists of unwanted sexualised comments, provocative gestures, honking, wolf whistles, indecent exposures, stalking, persistent sexual advances, and groping by strangers, in public areas such as streets, shopping malls and public transportation. Besides actions or comments that contain a sexual connotation, it often includes homophobic and transphobic slurs, and hateful comments referencing race, religion, class, ethnicity and disability. The practice is rooted in power and control and is often a reflection of societal discrimination, and has been argued to sometimes result from a lack of opportunities for expression of interest or affection (e.g. an inability to have social interaction).

Recipients include people of any gender, but women are much more commonly victims of harassment by men. According to Harvard Law Review (1993), street harassment is considered harassment done primarily by male strangers to females in public places.

According to the founder of Stop Street Harassment, it can range from physically harmless behavior, such as "kissing noises", "stares", and "non-sexually explicit comments", to "more threatening behavior" like stalking, flashing, grabbing, sexual assault, and rape.

In the 19th century London, street harassment came into the spotlight as a social issue. The emergence of new shopping districts near the West End caused many middle-class women to walk through traditionally male-dominated neighborhoods to purchase the latest goods. Women sometimes found themselves questioned and followed by men who worked in the area. The men's behaviors resembled contemporary working-class courtship rituals. In such rituals, a young man would show his preference for a woman by "glad-eyeing" her in the street, and the woman would respond by slowing down her pace.

According to Judith R. Walkowitz, the public's perception of street harassment was shaped by the middle-class women who were the new subjects of this courtship practice, which was perceived to be far too casual and informal to be proper. Their experience was given a greater weight by the society than those of working-class women. Leading ladies' journals of the era contained advice on how to avoid being "spoken to" by men when going about their business.

The modern discussion regarding the subject began in 1944 with the rape of Recy Taylor. Rosa Parks was commissioned to investigate the crime in which Taylor, a black woman, was kidnapped and gang-raped in Abbeville, Alabama. Parks responded by starting what was later dubbed the "strongest campaign for equal justice to be seen in a decade."

Physical responses, physical safety, emotional reactions, and psychological symptoms are the effects of street harassment. Physical effects can also be discussed in terms of the physical safety of a woman. Recipients of harassment describe physical symptoms as muscle tension, having trouble breathing, dizziness, and nausea. Street harassment evokes from its targets emotional responses that range from moderate annoyance to intense fear. Two themes repeatedly appear in women's responses to inquiries about the experience of harassment: the intrusion upon privacy and the fear of rape. Some scholars deem that comments and conduct of a harasser reduce women to sexual objects and force this perception upon his target. Harassment may also teach women to be ashamed of their bodies and to associate their bodies with fear and humiliation through reflections of self-blame. A study published in 2010 reported that the experience of street harassment is directly related to a greater preoccupation with physical appearance and body shame, and is indirectly related to heightened fears of rape. Women who self-blame are likely to experience distressing symptoms in the form of body shame, body surveillance, and self-objectification. Not only does this result harm a woman's self-esteem, but it may also interfere with her ability to be comfortable with her sexuality.

Street harassment severely restricts the physical and geographical mobility of women. It not only diminishes a woman's feelings of safety and comfort in public places, but also restricts her freedom of movement, depriving her of liberty and security in the public sphere. Women assess their surroundings, restrict choices of clothing, wear headphones, choose to exercise inside, and avoid certain neighborhoods or routes as proactive measures to reduce the chance of being harassed. In recent studies, street harassment was linked to indirect consequences that decrease the quality of women's lives. The decrease in quality of life is contributed to avoidant behaviors.