A janitor ( American English, Scottish English), janitress (female), custodian , porter , cleaner or caretaker is a person who cleans and maintains buildings such as hospitals, schools, and residential accommodation. Janitors' primary responsibility is as a cleaner. In some cases, they will also carry out maintenance and security duties. A similar position, but usually with more managerial duties and not including cleaning, is occupied by building superintendents in the United States. Cleaning is one of the most commonly outsourced services.
Most of the work performed by janitors and building cleaners is indoors, sometimes it can be outdoors. Outdoors work mainly include sweeping walkways, mowing lawns, or shoveling snow. In some facilities or buildings, a separate company may be hired to do outdoor work. Office buildings are usually cleaned when they are vacant, so most of the office janitorial staff work during the evening. The work can be physically demanding and sometimes dirty and unpleasant.  General janitor duties often include the following tasks:
- Cleaning and restocking bathrooms
- Cleaning floors (mopping, sweeping, polishing)
- Carpet cleaning (dry method, extraction, steam and bonnet)
- Cleaning carpeting (vacuuming)
- Cleaning stainless steel and other special surfaces
- Clearing lunch room/kitchen
- Cleaning tables in cubicles, meeting rooms, etc...
- Emptying trash and recycling bin
- Unlocking and locking buildings at the beginning and end of the day
- Stripping and waxing floors using Floor buffer
- Cleaning air-conditioner vents
- Crime scene cleaning (requires being fully certified and pay scale starts from $300.00 to $700.00+ an hour   )
- Litter picking
- Spot cleaning (generally spills - coffee for instance)
- Room setups (college/schools, etc.)
- Porterage (internal deliveries; movement of equipment or people in hospitals)
- Removing vomit and feces from public areas
- Raising and lowering flags (schools)
In 2010, the median pay of a janitor working in the US was $10.68 per hour. The yearly salary could grow by 11% according to the statistics of 2010. 
Office cleaning staff perform many of the same duties as janitors. However the tasks are divided among different members. Additional tasks include:
- watering plants (pruning as well)
- cleaning sinks, refrigerators, microwaves and toasters in office kitchens; clearing recycling and garbage bins
- dusting furniture and computer equipment (monitors and desk area, but excluding keyboards) and tables
Cleaning is one of the most commonly outsourced services.  Some of the reasons for this include:
- Basic cleaning tasks are standardised, with little variation among different enterprises.
- The nature of the job and required standard of performance can be clearly defined and specified in a contract, unlike more technical or professional jobs for which such specification is harder to develop.
- Some organizations prefer to outsource work unrelated to their core business in order to save additional salaries and benefits required to manage the work.
- Some organizations may feel uncomfortable dealing with labour relations related to low wage employees; by outsourcing, these labor relations issues are transferred to a contractor whose staff are comfortable and experienced in dealing with these issues, and their approach can benefit from economies of scale.
- If a janitor is unavailable due to sickness or leave, a contractor which employs many janitors can easily assign a substitute. A small organisation which employs one or a few janitors directly will have much more trouble with this.
Between 17% to 23% of the total undocumented immigrant population living in the United States work in the cleaning industry  (and growing at a rate of 1/2% to 1/3% percent per year). In addition to this population offering an abundant source of inexpensive labor,  janitorial work is mostly undertaken at night, making it an appealing option for janitorial companies to employ undocumented workers   seeking clandestine employment. Many such immigrants have even started their own janitorial companies using fictitious business licenses  and false identication   information.
In the Netherlands, the number of cleaning companies grew from 5,000 in 2003 to 8,000 in 2008.
In popular culture
The idea of the janitor, often as a figure of ridicule or pity, became a negatively stereotypical blue collar character in popular culture many times denoting ignorance, laziness, failure, exploitation or even perversion and have featured widely in film and television. Not all the janitors listed below, however, share these traits. The following are listed in order of first appearance.
- 1953: Mr. Svenson is a character who works as a custodian at Archie Comics' Riverdale High School
- 1964: Leader is a supervillain character that appears in comic books published by Marvel Comics ; in 2009, The Leader was ranked as IGN's 63rd Greatest Comic Book Villain of All Time
- 1966: Parasite is the name of several characters that appear in Superman comic book stories published by DC Comics ; a supervillain who has the ability to temporarily absorb the energy, knowledge and super-powers of another being by touch
- 1973: George Jefferson is a character played by Sherman Hemsley on the American television sitcoms All in the Family (1973–75) and its spin-off The Jeffersons (1975–85)
- 1974: Hong Kong Phooey is a mild-mannered police station janitor in the animated series of the same name
- 1974: OMAC is a superhero comic book created in 1974 by Jack Kirby and published by DC Comics
- 1978: Beauregard and George the Janitor are Muppet characters, who work as janitors
- 1979: Night Raven is a superhero appearing primarily in Marvel UK Comics, a division of Marvel Comics, first appearing in Hulk Comic #1 (March 7)
- 1982: Brian Banner is a villainous character from the Marvel Comics Universe, the abusive father of Bruce Banner ( Incredible Hulk), and is featured in the 2003 film Hulk (though renamed David)
- 1984: Freddy Krueger ( Robert Englund) is the main antagonist of the A Nightmare on Elm Street film series
- 1985: Philip Martin is a character from the Australian soap opera Neighbours , played by Ian Rawlings (originally played by Christopher Milne)
- 1985: Carl Reed is a janitor in the 1985 American coming-of-age comedy-drama film The Breakfast Club , played by John Kapelos
- 1986: Booster Gold is a DC Comics superhero and a member of the Justice League, initially depicted as a glory-seeking showboat from the future, using knowledge of historical events and futuristic technology to stage high-publicity heroics
- 1986: Forrest Gump is a character who, in the second novel of the series, Gump and Co. , works as a janitor in a New Orleans bar
- 1986: Roger Wilco is a janitor and the protagonist of the Space Quest series, introduced in Space Quest: The Sarien Encounter ; he was on the 2004 list of "top ten working class heroes"
- 1986: Skeets is an artificial intelligence robot from the future in the DC Comics Universe; usually seen as a companion to Booster Gold, he co-stars in the limited series 52 and the subsequent Booster Gold vol. 2
- 1989: Stanley Spadowski is a dim-witted but excitable janitor in the comedy film UHF , portrayed by Michael Richards
- 1991: Groundskeeper Willie is a recurring character on the animated comedy series The Simpsons who works as a groundskeeper
- 1997: Ethan Hawke plays a janitor who has a handicap who switches DNA identities with another man in Gattaca
- 1997: Matt Damon plays a janitor and a self-taught genius in the drama film Good Will Hunting
- 2000: Marty Murray is a character from Channel 4 soap Brookside played by Neil Caple from 2000 until 2003
- 2000: The Janitor's Boy is a children's book by Andrew Clements about a young boy whose father is a janitor
- 2001: Frazz is a syndicated comic strip by Jef Mallett that, on the surface, is about school custodian Edwin "Frazz" Frazier and the school where he works, but which, according to Mallett, is really about discovery
- 2001: The Janitor is a fictional character, played by actor Neil Flynn in the American comedy-drama Scrubs , who works as a janitor at Sacred Heart
- 2001: Joe Dirt is an American adventure comedy film about a " white trash " young man working as a custodian, Joe Dirt, who at first seems to be a "loser", a failure, an antihero
- 2001: Thomas Logan is a fictional character in the Marvel Comics universe – the biological father of Wolverine of the X-Men, who works as a groundskeeper
- 2001: Scruffy is an apathetic and perverse janitor on the animated series Futurama , voiced by Billy West
- 2005: Charlie Kelly is a character on the sitcom It's Always Sunny in Philadelphia
- 2006: The film Flags of Our Fathers shows one of the famous Iwo Jima flag raisers who spends the rest of his life as a janitor
- 2006: The Miniature Killer is a fictional character on the CBS crime drama CSI: Crime Scene Investigation , portrayed by Jessica Collins
- 2008: WALL-E is a robot who has developed sentience, the only robot of his kind shown to be still functioning on Earth, and works diligently to fulfill his directive to clean up the garbage on Earth