Don't Miss a SecEdit profile
The person inside the cube can see passers-by but is invisible to them
Monica Bonvicini said visitors would have to "defy their own embarrassment" to use the minimalist cubicle, made from one-way mirrored glass.
It is impossible to see into the toilet, which will be free to use, but the person inside can see passers-by.
The work, called Don't Miss A Sec, uses a prison loo as a historical reference.
The site - on the old parade ground at the former Royal Army Medical College - once housed Millbank Penitentiary, where prisoners were held before being transported to Australia.A spokeswoman for the artist said: "It will arouse curiosity because people can come and just use it, although there is a question of whether people will feel comfortable doing so.
"They may be wary of desecrating a work of art or may be uneasy that because they can see out, other people can see in.
"There could be this feeling that there is some form of switch to change it and let people see in, but of course there isn't."
Ms Bonvicini, born in Italy but based in Los Angeles, is known for using her work to make people question their environment.
The installation will open for two hours from 1800 GMT each week day, from 1400 to 1800 GMT on Saturdays and 1000 to 1800 GMT on Sundays.
Ms Bonvicini is not alone in using a toilet to bring art to the public.
In October, two artists opened The Toilet Gallery - a converted public loo in Kingston-upon-Thames, south-west London, showcasing young artists from across Britain.
Read a selection of your comments below.Fantastic idea, I'd love to go in it! It's got me thinking how amazing it would be to have a whole house made out of one way glass - the possibilities are endless!
Maisie, Wales, UK
Wow, what a novel idea to watch the world go by while doing your daily routine. I am sure there are those who would love to be watched also with a two way mirror.
In my opinion Monica Bonvicini realized a great example of modern art. She fused practise (the materials) and art in a simple water! She is great!
Michela Torazza, Italy
The two way mirrors thing is nothing new - nor the fact that you can see into the gents from the ladies. I seem to remember visiting a nightclub though where the mirrors in the ladies - i.e. where they did their make-up allowed gents using the urinals to watch women doing their make-up and sometimes more!
Mike Bailey, Austria
This is all very well during daylight, but what happens at night? Surely there's not a light bulb inside, or things could get very interesting!
Robert Salm, USA
Ahhhh... finally an artist with toilet humour!
Kelsey Liu, USA
Alex Tod, UK
Being able to watch the world go by while you lighten your load will probably enhance the toilet experience much more than reading a newspaper.
I think the work should be inside the Tate rather than outside. It seems eminently appropriate that one should be able to relieve oneself while viewing some of the "art" that has crawled its way in there over the past few years.
Andy Kimber, UK
Ms Bonvicini is a bit too late. The Buzz Cafe in Darwin, Australia has had a one way mirrored men's toilet for years. The glass is actually the urinal which you urinate on. Great fun with a dining area on the other side!
Shaun Payne, Lebanon (ex UK)
This is a variant on an idea I once saw in a bar in the US, only there it was the other way round. The wall above the men's urinals appeared to users to be a mirror. In the bar, however, the customers could see the chaps lined up doing their business (though only as far down as the chest!)
Jon Sutcliffe, UK
This reminds me of the Peninsula hotel in Kowloon, Hong Kong. The gents urinals are mounted along a glass wall, so as you relieve yourself you can watch the world go by. Of course, the building is very tall so there are no passers-by, but before they opened the new airport 747s would pass by the front of the hotel within "viewing" range!
Mark Kobayashi-Hillary, London, UK
Good God! An artist with imagination. Give her a British passport and beg her to stay.
So, just like any telephone box in London then!
Michael A. Houlsby, UK
Could David Blaine use this next time?
Sundeep Malhotra, London, UK
I think this is great fun, but it's only a matter of time before some couple try to do more than have a pee in there!
Graham, Chichester, UK