A public toilet, restroom, public bathroom or washroom is a room or small building with toilets (or urinals) and sinks for use by the general public. The facilities are available to customers, travelers, employees of a business, school pupils and prisoners and are commonly separated into male and female toilets, although some are unisex, especially for small or single-occupancy public toilets.

Increasingly, public toilets are accessible to people with disabilities. Depending on the culture, there may be varying degrees of separation between males and females and different levels of privacy. Typically, the entire room, or a stall or cubicle containing a toilet, is lockable. Urinals, if present in a male toilet, are typically mounted on a wall with or without a divider between them. Local authorities or commercial businesses may provide public toilet facilities. Some are unattended while others are staffed by an attendant. In many cultures, it is customary to tip the attendant, especially if they provide a specific service, such as might be the case at upscale nightclubs or restaurants.

Public toilets are typically found in many different places: inner-city locations, offices, factories, schools, universities and other places of work and study. Similarly, museums, cinemas, bars, restaurants, entertainment venues usually provide public toilets. Railway stations, filling stations, and long distance public transport vehicles such as trains, ferries, and planes usually provide toilets for general use. Portable toilets are often available at large outdoor events.

Public toilets may be municipally owned or managed and entered directly from the street. Or they may be within a building that, while privately owned, allows public access, such as a department store, or it may be limited to the business's customers, such as a restaurant. Some public toilets are free of charge while others charge a fee. In the latter case they are also called pay toilets and sometimes have a charging turnstile. In the most basic form, a public toilet may just be a street urinal known as a pissoir, after the French term.

Public toilets are known by many other names depending on the country. Examples are: restroom, bathroom, men's room, women's room, powder room in the US, washroom in Canada, and toilets, lavatories, water closet (W.C.), ladies and gents in Europe.