A room in mental institutions to which patients are sent, dragged, or carried when staff consider them violent, self-injurious, or simply annoying. The room may contain a bare floor, a mattress, a table, or a bed. The patient may be stripped, tied down with restraints, wrapped in a wet blanket, drugged, or left on his own. He may stay there from hours to days. There is generally a small observation window or mirror through which staff or patients can view the inmate. Also known as the seclusion or isolation room. Similar to solitary confinement.

Although America has laws in place to restrict the use of such rooms on the whims of staff, they range from difficult to impossible to enforce.

The Quiet Room is also the title of a book by Lori Schiller, documenting her recovery from schizophrenia.