The proportion of women facing harassment is higher among the youngest workers - nearly two-thirds (63%) of the 138 women aged between 18 and 24 surveyed said they had been sexually harassed at work.
Young women were often on casual contracts, such as temporary agency or zero-hours contracts. They were also likely to be in more junior roles, all of which may be factors in sexual harassment, said the TUC.
The survey also found:
- More than one in four (28%) respondents were the subject of comments of a sexual nature about their body or clothes at work
- A fifth (20%) suffered unwanted verbal sexual advances at work
- And around one in eight (12%) experienced unwanted sexual touching or attempts to kiss them at work
Ms O'Grady added: "They have to ask why it is we are not stamping this kind of behaviour out. We have been calling for tougher action from employers and we want the government to send a clear signal that this kind of behaviour is unlawful.
"I think the most worrying fact from these findings is the number of women who simply don't feel able to report it. "
One young woman told the TUC anonymously that in her previous job she worked in an almost exclusively male salesroom.
"Sexual comments about me or others, either to me or overheard in my presence, were a fact of daily working life. Some of those comments were violent in nature," she said.
Your rights
The Citizens Advice Bureau urges people to act as quickly as possible if they fall victim to sex discrimination or sexual harassment at work, suggesting:
- Tell the person to stop, if you feel it is safe to do so
- Tell your manager what is happening. Put it in writing and keep a copy
- Talk to your personnel department or trade union
- Get advice
- Collect evidence by keeping a diary of any incidents, including time, date and location, what was said or done, who was involved and any witnesses
- If informal procedures are unsuccessful, raise a grievance with a formal written complaint to your employer
'Alive and well'
Laura Bates, founder of the Everyday Sexism Project which helped with the report, said many people would like to think that workplace sexual harassment was a thing of the past.
"In reality it is alive and well, and having a huge impact on tens of thousands of women's lives."
Men have also been victims of sexual harassment at work, with one, Simon, telling BBC News: "I frequently get touched on the upper arm, called 'darling' or 'sweetheart'.
"I do not like it, I do not invite it and am unsure how to respond. I am male and the perpetrators are female. I would feel a wuss if I were to complain. This does not just happen to females."
Have you, or has someone you know, been affected by sexual harassment at work? Was it reported? Email haveyoursay@bbc.co.uk
Please include a contact number if you are willing to speak to a BBC journalist. You can also contact us in the following ways:
- Email haveyoursay@bbc.co.uk
- WhatsApp: +44 7525 900971
- Send pictures/video to yourpics@bbc.co.uk
- Or Upload your pictures/video here
- Tweet: @BBC_HaveYourSay
- Send an SMS or MMS to 61124 or +44 7624 800 100