"Ghostbusters" is a 1984 song recorded by Ray Parker, Jr. as the theme to the film of the same name that starred Bill Murray and Dan Aykroyd. It hit number one on the Billboard Hot 100 on August 11 in 1984, and stayed there for three weeks. It also peaked at number two on the UK Singles Chart on 16 September 1984, where it stayed for three weeks. The song is performed in the key of B major.

It was nominated for the Academy Award for Best Music, Original Song, but lost to Stevie Wonder's "I Just Called to Say I Love You".

According to Parker, he was approached by the film's producers to create a theme song for the film. Unfortunately, he only had a few days to do so and the film's title seemed impossible to include in any lyrics. However, when watching television late at night, Parker saw a cheap commercial for a local service that reminded him that the film had a similar commercial featured for the fictional business. This inspired him to write the song as a pseudo-advertising jingle that the business could have commissioned as a promotion.

Parker was later the defendant in a copyright-infringement lawsuit which claimed "Ghostbusters" was too similar in musical structure to "I Want a New Drug", written and performed by Huey Lewis and the News (more specifically, the guitar riff which runs through the song). "I Want a New Drug" was a U.S. top-ten hit earlier the same year. The two parties settled out of court. Details of the settlement (specifically, that Parker paid Lewis a settlement) were confidential until 2001, when Lewis commented on the payment in an episode of VH1's Behind the Music. Parker subsequently sued Lewis for breaching confidentiality; the lawsuit is ongoing. Ironically, Lewis had at one point been asked to record a theme song for the movie, but turned it down for other commitments.

In later years, AutoNation adopted the theme for their advertising campaign. In the United Kingdom, the song is parodied with Parker himself being featured in a commercial advertising direct enquiries line 118 118.

The song re-entered the UK Top 75 on 2nd November 2008 at #49.

Lindsey Buckingham claims to have been approached to write the Ghostbusters theme based on his successful contribution to Harold Ramis's National Lampoon's Vacation (the song Holiday Road). He turned down the opportunity as he didn't want to be known as a soundtrack artist. He mentions this on the "Words & Music" interview disk.

A music video for the song featured a young woman, played by Cindy Harrell, who was being haunted by a ghost portrayed by Parker, roaming a nearly all-black house interior with vibrant neon designs outlining the sparse architectural and industrial features. It also contained footage from the film Ghostbusters, and featured cameos from many celebrities of the day, including Chevy Chase, Irene Cara, John Candy, Melissa Gilbert, Nickolas Ashford, Jeffrey Tambor, George Wendt, Al Franken, Danny DeVito, Carly Simon, Peter Falk and Teri Garr, all of whom exclaim the "Ghostbusters!" line of the song when shown.

The video concludes with Parker and the stars of the film, in full Ghostbuster costume, dancing down the streets of New York City. The Ghostbusters also performed the similar dance in the closing credits to the Real Ghostbusterscartoon series as well as in a trailer for the 2009 video game.

Due to the ongoing legal battle between Parker and Huey Lewis, the video has not been included in any release of the movie on home video to date.

The song is referenced in both the films and the cartoon series.

In Ghostbusters II, at one point in the movie, Peter Venkman says, "Kitten, I think what I'm saying is that sometimes, shit happens, someone has to deal with it, and who you gonna call?" There was also a scene where a commercial for the company's business featured Janine Melnitz and Louis Tully as a couple being bothered by a ghost. Louis picks up a phone, Janine asks who he is going to call, and the Ghostbusters appear answering "Ghostbusters!" Also, in the birthday party scene at the beginning of the movie, Raymond Stantz and Winston Zeddemore play and sing along to the song.

In an episode of The Real Ghostbusters, the Ghostbusters are trapped in an alternate reality New York populated by ghosts, where a group of ghosts called the Peoplebusters go around the city catching human beings. When they are fleeing from the Peoplebusters, the GBs pass a ghost dining in an outdoor cafe, who witnesses the scene and sings "When there isn't something strange/in your neighborhood/Who you gonna call?/Peoplebusters!"

In TokyoPop's Ghostbustersseries, Ray, Peter and Egon eat at a diner with pictures of famous patrons on the wall. Ray comments on the people on the wall, and, finding Ray Parker Jr, remarks that he's never heard of him.

The song appears in Ghostbusters: The Video Game.

St. Louis CBS station KMOV spoofed the song for its mid-1980s "Newsbusters" promos.

Washington, DC NBC station WRC-TV spoofed the song in 1988 with "Broncobusters", which is all about the Washington Redskins and their, at the time, upcoming match up against the Denver Broncos at Super Bowl XXII.

The British band McFly also performed the song as it is one of the lead singer's (Tom Fletcher) favorite songs.

Professional wrestler Jerry Lawler made a parody of the song in Memphis Wrestling entitled "Wimpbusters".

In the 1995 movie Casperwhen Carrigan and Dibbs are trying to get the ghosts out of the mansion, several pieces of furniture are thrown out of the door, and Dan Aykroyd (dressed as his Ghostbusterscharacter, Dr. Raymond Stantz) is seen running out. He stops by Carrigan and Dibbs and says, "Who you gonna call? Somebody else." He then leaves quickly.

In the television series Buffy the Vampire Slayer, Spike asks Buffy, "Who you gonna call?" then follows it with "God, that line is never gonna be usable again, is it?" to which she replies, "Probably not."

Disney produced an abridged music video of the song in the special DTV Monster Hits, set entirely to clips from the 1937 cartoon Lonesome Ghosts.

A musical number on the Kids' WB! show Histeria!, about Theodore Roosevelt and his anti-trust campaign (featured in the episode "The Teddy Roosevelt Show"), was sung to the theme.

In the "Petergeist" episode of Family Guy, Tom Tucker reports that the Griffin family's house is infested with ghosts. "Who they gonna call?" he asks. His co-anchor, Diane Simmons, suggests "Ghostbusters?" and Tucker replies with "No, Diane, their insurance company. That's just stupid what you said."

In an episode of the TV show Max and Paddy's Road To Nowhere, a motor mechanic who goes by the name of Mick Bustin has the slogan "When there's something strange/Underneath your hood/Who ya gonna call?/Mick Bustin" for his business, and Ghostbuster parody logos all over his auto shop.

In the "Bloooo" episode of Foster's Home for Imaginary Friends, when Wilt asks Coco what to do for their "ghost" problem, Coco picks up a telephone, and Wilt says, "Who you gonna call?" Coco responds by saying "Co-coco!" in the same way the word Ghostbusters is said in the song. Wilt replies, "Nah, they've been out of business for years."

The BBC children's comedy series Maid Marian and her Merry Menfeatured a spoof of the song entitled "Call The Dentist".

In Sonic Unleashed(PlayStation 3 and Xbox 360 versions) there is an achievement called "I Ain't Afraid of No Ghost", which is unlocked by freeing several NPCs from possession. It is also the name of an achievement in the Xbox 360 version of the Ghostbusters game that is unlocked after the player traps the Sloth Ghost.

A recent advert for UK Directory Enquiries service 118-118 features Ray Parker Jr. (multiple times in different costumes including a mailman, a mechanic, a waiter and a bus conductor) in a parody of the song he originally recorded for Ghostbusters. It alters lines slightly such as "If there's something strange, going through your head, Who Ya Gonna Call? 118!", "Who can you call? 118!" and "I ain't afraid of no goats" (shortly after he frees two goats from the back of a car). The advert also features giant versions of the 118 men, in a parody of the Stay Puft Marshmallow Man.

Ads for the Maroone car dealerships(Auto Nation affiliate of Palm Beach and Broward County, South Florida) featured variations on the famous chorus. The variation went: "If you need a car/Truck or van/Who you gonna call/MAROONE!". Other Auto Nation affiliates (ex: AutoWay of Tampa, Courtesy of Orlando) use this song for their advertisements.

In the Doctor Whoepisode "Army of Ghosts", a couple lines of the song are sung by both The Doctor and Rose Tyler, the Doctor carrying equipment that visually resembles the equipment the Ghostbusters used.

A parody version sung by the dead character Nappa ('Ghost Nappa') was used to close the first season of That Guy with the Glasseshosted Dragon Ball Z Abridged.

The song is one of the playable songs in Lego Rock Band, both in the console versions and in the Nintendo DS version.

In the episode "The Gang Solves the Gas Crisis" in the FX sitcom It's Always Sunny in Philadelphia, the gang references the Ghostbusters a few times during the episode, and drive around the city to the theme song.

John and Edward (Jedward) performed this on X Factor November 7, 2009.

"Ghostbusters" was made a playable song in Beatmania IIDX 14 Gold. It is also a playable song in LEGO Rock Band.