- "You know the Prefects' bathroom on the fifth floor? It's not a bad place for a bath."
- —Cedric to Harry Potter on the Prefects Bathroom[src]
The Prefects' bathroom is a special bathroom on the fifth floor of Hogwarts restricted to use by school Prefects, Head Boys, Head Girls and Quidditch captains. It is located on the fifth floor behind the fourth door to the left of a statue of Boris the Bewildered, which only opens when given the correct password.
In one side of the room there are the stalls with toilets inside.  Opposite the toilets there is a large, swimming pool-like tub with bath taps surrounding it.The pool-like bath is sunk into the ground and is not above ground. The bath taps all run different-coloured bath water, soap bubbles, foam, towels, and bath robes.These bath taps are a hundred golden taps surrounding the whole pool-like tub, with a different jewel set in each tap. There are most likely bath supplies on one side of the pool, such as soap, bath oil, bath powder, bath salts, shampoo, hair spray, and conditioner. Looking at the tub, one would imagine it would take quite some time to fill, but it actually fills remarkably fast, considering its size. Under the bathroom there are sewers that can be entered by blasting one section of the wall. These sewers may or may not be a part of the passages and tunnels of the Chamber of Secrets.
After the first task of the Triwizard Tournament, Barty Crouch Jr., disguised as Alastor "Mad-Eye" Moody, tells Cedric Diggory to open the golden egg that contains the clue for the second task under water. Cedric takes the egg to the prefects' bathroom and follows Crouch's advice. Underwater, he can hear the merpeople's song, but it takes him some time to deduce that it is sung by merpeople, despite the fact that the mermaid in a nearby painting is wide awake. Moaning Myrtle, who visits this bathroom sometimes to spy on the prefects, witnesses the scene. Cedric then told Harry, in return for telling him about the first task: dragons.
After the Yule Ball, Cedric Diggory tells Harry Potter to try to solve the riddle of the golden egg while taking a bath in the prefects' bathroom. He also gives him the current password, which is "pine fresh". Harry follows his advice in the night of 21 January, 1995. Awed as he is by the bathroom, he has no idea at first how a bath is going to help him solve the egg's clue. He fills the pool with water and bubble bath from several taps, takes a short swim and opens the egg. As usual, it emits a loud, wailing noise and he closes it quickly. Moaning Myrtle reveals her presence and tells him to open the egg under water, like Cedric did. To Myrtle's delight, Harry solves the clue much faster than Cedric.
One of the first things Hermione Granger mentions when she congratulates Harry for becoming Captain of the Gryffindor Quidditch team in 1996 is that he can now use the prefects' bathroom. Ron Weasley also mentions it while congratulating Harry. It is unknown whether Harry ever used the bathroom in his sixth year. It has pictures of mermaids on stained glass windows.
- Pine Fresh
Behind the scenes
- In the video game adaptation of Harry Potter and the Goblet of Fire, there is a very long level in which Harry, Ron, and Hermione trek through the bathroom's plumbing areas in search of the golden egg, which Ron has dropped into one of the pipes.
- In the video game adaptation of Harry Potter and the Order of the Phoenix, the bathroom can be freely visited by the trio. The golden egg still sits in the tub, and screeches its noise unless the tub is filled enough that the egg is covered by water, which can be achieved by casting Banishing Charm on the taps. The mermaid's song can then be understood. The tub can be emptied again by pulling the plug with the Summoning Charm. A rubber duck sits on the tub's edge.
- There is a short level in LEGO Harry Potter: Years 1-4, where Harry must find the entrance to The Prefects' Bathroom (which is now in Moaning Myrtle's bathroom) and then persuade the mermaid on the window to throw the egg to him.
- In LEGO Harry Potter: Years 1-4, Harry wears his underwear to go in the giant bathtub instead of being naked.
- It is unclear whether the bathroom locks itself automatically when someone is using it. Harry worries he might be caught by Argus Filch when he is mulling over the egg clue in Harry Potter and the Goblet of Fire, so the person going in does not lock the door, but the fact that both girls and boys can use the bathroom suggests there must be some way to ensure privacy.
- Harry Potter and the Goblet of Fire (First appearance)
- Harry Potter and the Goblet of Fire (film)
- Harry Potter and the Goblet of Fire (video game)
- Harry Potter and the Order of the Phoenix (Mentioned only)
- Harry Potter and the Order of the Phoenix (video game)
- Harry Potter and the Half-Blood Prince (Mentioned only)
- Harry Potter and the Half-Blood Prince (video game) (Entrance only)
- LEGO Harry Potter: Years 1-4
Notes and references
Art Classroom · Boys' Restroom · Classroom · Classroom 5B · Corridor · Hall · Hospital tower corridor · Muggle Studies showroom · Music Classroom · Prefects' bathroom · Secret Muggle Room · Storeroom · Upper Hall · Weasley Candy Emporium · Weasley Supplies Bargain Basement