More than 40% of young women in the capital have experienced sexual harassment in public spaces over the last year, according to a poll.
A YouGov survey asked females about their experience of unwanted contact or attention such as wolf-whistling, sexual comments, staring or exposure of a sexual nature in London over the past 12 months.
The research for the End Violence Against Women Coalition found that 41% of women aged 18 to 34 had experienced unwanted sexual attention in public spaces, while 21% of women of all ages had experienced unwanted sexual attention and 4% of all women had experienced unwanted sexual touching.
The survey also asked female Londoners the same questions about their experiences while on public transport in the capital, and found 31% of women aged 18 to 24 experienced unwanted sexual attention, 14% of women of all ages experienced unwanted sexual attention, while 5% of all women experienced unwanted sexual touching.
Coalition co-chairwoman Professor Liz Kelly said: "Our survey shows that sexual harassment in London is extremely common.
"Some survey respondents also said that this behaviour makes them feel uncomfortable and unsafe and makes them change their behaviour and decisions about when and where to travel.
"Despite this high prevalence and impact however, public sexual harassment is a form of abuse which generally goes unchallenged, creating an unsafe and unequal environment for women.
"We need investment in public campaigns on transport and elsewhere saying this behaviour is unacceptable, and training for transport staff and police about how to respond to it."
Women who responded to the survey described having to change carriage or leave a stop early after experiencing harassment on the train or tube, while others said they avoided sitting on the top decks of buses.
The coalition commissioned the YouGov survey in order to highlight the every day impact of women's safety fears, which it said are strongly related to the threat and reality of violence in the lives of thousands of women and girls.
It said that last year 45,000 incidents of domestic violence and 3,000 rapes were reported to police in London.