The Hitchhiker's Guide to the Galaxy is a BBC television adaptation of Douglas Adams' The Hitchhiker's Guide to the Galaxy which aired between 5 January and 9 February 1981 on BBC Two in the United Kingdom. The adaptation follows the original radio series in 1978 and 1980, the first novel and double LP, in 1979, and the stage shows, in 1979 and 1980, making it the fifth iteration of the guide.
 The series stars Simon Jones as Arthur Dent, David Dixon as Ford Prefect, Mark Wing-Davey as Zaphod Beeblebrox, Sandra Dickinson as Trillian and Stephen Moore as the voice of Marvin. The voice of the guide is by Peter Jones. Peter Jones, Simon Jones, Moore and Wing-Davey reprised their roles from the original radio series in 1978/80, as did supporting actors Richard Vernon and David Tate. In addition, the series features a number of notable cameo roles, including Adams himself on several occasions.
 Although initially thought by BBC executives to be unfilmable, the series was successfully produced and directed by Alan J. W. Bell and went on to win a Royal Television Society Award as Most Original Programme of 1981, as well as several British Academy Television Awards for its graphics and editing.
 After the success of the first seven episodes of the radio series, all broadcast in 1978, and while the second radio series was being recorded, Douglas Adams was commissioned to deliver a pilot script for a television adaptation on 29 May 1979, to be delivered by 1 August. A fully animated version was briefly discussed in the autumn of 1978, but it was eventually decided to make most of the series feature "live action" and only animate The Guide's entries. John Lloyd, who had worked with Adams on the first radio series, is credited with starting the process of adapting the series for television, after the receipt of the pilot script, with a memo to the head of light entertainment (John Howard Davies) in September 1979. Adams was still working on scripts for the second radio series of Hitchhiker's and working as script editor for Doctor Who, and thus the BBC extended the deadline for the pilot script of the television adaptation to the end of November. The script for the pilot was delivered in December 1979, and terms for the five remaining scripts were agreed upon in January 1980. While there was some resistance to a project considered "unfilmable," Alan J. W. Bell was given the duties to produce and direct the television adaptation. John Lloyd was signed as associate producer.
 In early 1980, production on the pilot episode began on several fronts. Rod Lord of Pearce Animation Studios directed a 50-second pilot, hand-animated, giving a 'computer graphic' feel to the Babel Fish speech of the first episode. Douglas Adams and Alan J.W. Bell were both pleased with the animation, and Lord was given the go-ahead to do all of the animation for episode one, and subsequently the complete television series. Narration for the first episode was recorded by Peter Jones in March 1980. The filming of two green-skinned aliens reacting to Pan Galactic Gargle Blasters was done on 8 May 1980. Further filming of crowd reactions to the Vogons, location filming of Arthur's house and a scene in a pub were done between 11 and 16 May 1980. Scenes aboard the Vogon ship were recorded on 7 June 1980, in the BBC's TC1 studio. The final edit of the pilot episode was completed on 2 July 1980, and it was premiered for a test audience three days later (5 July). Further test screenings were held in August 1980. Based on successful test screenings, the cast was reassembled to complete the six episodes of the series in September 1980. Production continued through the autumn, with filming and recording occurring out of order. Recording and production of the final episode continued into January 1981.
 The gap in production made for some continuity problems between the pilot episode and the remainder. Notably, Simon Jones' hair was cut short for another role and he wears a noticeable hairpiece in later episodes. Conversely, David Dixon's hair appears longer.
 One major change first appeared in the stage show and LP adaptations, and made its way into the novels and television adaptation. Nearly all of the sequences from episodes five and six in the first radio series that were originally co-written with John Lloyd were completely cut. Thus the Hotblack Desiato character and Disaster Area make appearances in episode five, and Ford, Arthur, Zaphod and Trillian are all randomly teleported off of Disaster Area's stunt ship in episode six. Lloyd does receive a co-writer's credit on episode five, for the material on the statistics about the universe. The complexities of adapting the material for television meant that some episodes became as long as 35 minutes; as a result, material that had appeared in the radio series (e.g.: the seance involving Zaphod's ancestors) had to be cut. The programme is particularly notable for its mock computer animation sequences, actually produced on film using traditional cel animation techniques. There have been several different edits of the series: Some, but not all, American PBS stations recut the series into seven 30-minute episodes when they began transmitting the episodes nearly two years later, in December 1982. Other PBS stations re-edited the programme into television movies, broadcasting more than one episode at a time without interruption. The UK videotape release was on two cassettes, each consisting of three episodes edited to run together and also adding some previously unseen material. The soundtrack was remixed into stereo. The North American VHS tape released by CBS/Fox Video included this material on a single video cassette. The DVD edition claims to be the final and definitive version of the six television episodes.
 Another production problem was that, being a visual adaptation, a solution had to be found to display Zaphod's three arms and two heads, a joke originally written for radio. In a previous stage adaptation, a version of a pantomime horse was used, where two actors filled one costume, providing three arms and two heads between them. For this television series, a radio-controlled animatronic head was designed and built, incorporating twelve servo motors and two receivers. However, the head was notoriously unreliable and in many scenes merely sits there, inanimate. For the third arm, most of the time it was seen tucked into Zaphod's jacket. But when called for Mike Kelt, who had designed the extra head (with make-up, hair and prosthetics designer Joan Stribling) would hide behind Mark Wing-Davey and slip his arm into the appropriate sleeve.
 Other elements to the production were done by a variety of BBC designers. The Heart of Gold and B Ark models were built by Perry Brahan. The small, furry creature from Alpha Centauri in episode three was a puppet designed and controlled by Jim Francis, who also built the Magrathean bubble car (also seen in episode three), and was the stunt double for Richard Vernon in the scene in which the bubble car was seen to fly. Matte paintings throughout the series were created by Jean Peyre. Music and sound effects were by Paddy Kingsland, with the exception of the theme music; the familiar Journey of the Sorcerer theme by Bernie Leadon was used again, in the arrangement by Tim Souster that had previously been used for the Hitchhiker's LP. Video effects using the Quantel system were done by Dave Jervis. Other puppets, including insects seen in episode five, were designed by Susan Moore. Some of the actual puppeteering was done by Stuart Murdoch, including operating parts of the Dish of the Day animal. Two important cast changes were made for the television version. David Dixon replaced Geoffrey McGivern as Ford, and Sandra Dickinson replaced Susan Sheridan as Trillian. The changes were made because McGivern did not suit the role visually, and Sheridan was unavailable at the time. Another new cast member was Michael Cule, who appears as the Vogon guard in episode two. Cule had first appeared in one of the Hitchhiker's stage adaptations, performing no fewer than twelve roles. He reprised the Vogon guard part in the 1992 Making of the Hitchhiker's Guide to the Galaxy television documentary, voiced the Babel fish, appeared in the 1994 photo illustrated edition of the book (as Prosser), and returned a third time as a Vogon guard for the BBC Radio 4 Quandary Phase.
 Because of the sheer number of models used in episodes two to six, a single day of filming just the model sequences was set aside at the BBC Television Centre on 28 October 1980. This has been described as "a luxury few other shows could afford".
To provide proper timing of spoken lines on-set, as Douglas Adams himself spoke the lines of Eddie the Computer and Deep Thought, until they were redubbed by David Tate and Valentine Dyall respectively. Adams had several cameo appearances during episodes one to three in the television series:
 The hand-animated "computer graphics" of The Hitchhiker's Guide itself won a BAFTA, a Design and Art Direction Silver award, and a London Film Fest award. The spaceman suspended from a wire in the opening title sequence was Alan Harris. Locations for filming included a clay pit and the former Par-Fowey railway tunnel in Cornwall, the Edmonds Farm and Red Lion pub in Haywards Heath, Sussex, the Budgemoor Golf & Country Club near Henley-on-Thames, and at Dovestones in the Peak District National Park. Episode three was originally scripted to have a "pre-credits sequence" where Trillian announces their arrival at "the most improbable planet that ever existed", Magrathea, to Zaphod. This was never filmed. The arrangement of Journey of the Sorcerer by Tim Souster, used in the titles, was released as a single in the UK in January 1981. The B-side featured Douglas Adams playing rhythm guitar. Many of the costumes seen in episodes one to four can be seen again during sequences at Milliway's in episode five, as well as the writing at the start showing 42 crossed out several times also includes the number 101010 which is the 42nd number in the binary number base.
 A second series was planned at one point, with a storyline, according to Alan Bell and Mark Wing-Davey, that would have come from Adams' abandoned Doctor Who and the Krikkitmen project (instead of a television version of the second radio series). However, Adams got into disputes with the BBC (accounts differ: problems with budget, scripts, and having Alan Bell or Geoffrey Perkins involved were all offered as causes), and the second series was never made. The elements of the Doctor Who and the Krikketmen project instead became the third novel, Life, the Universe and Everything.
 In 1992, Kevin Davies wrote and directed a documentary entitled The Making of the Hitchhiker's Guide to the Galaxy. Davies had previously worked on the stage show at the Rainbow Theatre, and while working for Pierce Animation Studios in 1980, had introduced Alan Bell to Rod Lord, leading to the animation for the television series. For the documentary, Davies used many photographs and home movies he shot during the 1980 production of the series and recorded new interviews in October 1992 with the cast and crew. New footage of Simon Jones, David Dixon and Michael Cule, in character, were shot at the farm in Sussex used as Arthur Dent's house, and incorporated into the documentary with some references to So Long, and Thanks for All the Fish, such as Arthur finding his home intact, and placing his (animated) Babel fish into a goldfish bowl. BBC Video released the 60-minute documentary on VHS in 1993. Footage not included in the original documentary was included in the 2002 DVD release of the series. The documentary itself has not (as of 2005) been transmitted on television.
 Neil Gaiman reveals in the first edition of his biography of Douglas Adams, Don't Panic, that the BBC was preparing a Laserdisc release of the Hitchhiker's television series in the mid-1980s, but had to cancel the project due to a legal tangle with the movie rights, although master tapes for the Laserdiscs were prepared. The sound was specially remixed in stereo and Elektra/Asylum records agreed to license the original Eagles theme music. The series was eventually released on VHS format by BBC Video in 1992. This was a dual cassette edition featuring additional material that had originally been cut from the broadcast episodes. CBS/Fox Video made the six episodes available on a single VHS tape in North America starting in 1993. They were joined by The Making of the Hitchhiker's Guide to the Galaxy, also on VHS, that same year, as well as a Laserdisc release. A double tape box set edition was also released featuring the collected complete series and Making Of releases. Restoration of the six episodes and the Making Of documentary commenced in 2001, with a Region 2 and 4 DVD release in the United Kingdom by BBC Video (Catalogue Number BBCDVD 1092) in January 2002. A Region 1 edition, released by Warner Home Video, followed in April 2002. Both DVD editions are two-disc sets, with the six episodes on the first disc and accompanying bonus materials on the second. The North American DVD edition also has a copy of the Omnibus tribute to Douglas Adams from BBC Two that aired on 4 August 2001, which the UK DVD edition does not.
 A special edition box set of the series was released on Blu-ray and DVD on 1 October 2018. The set featured upscaled HD versions of the original episodes alongside optional stereo or 5.1 surround sound mixes remastered by Mark Ayres, formerly of the BBC Radiophonic Workshop.
 In North America, the complete series is viewable on Hulu, Amazon Prime and BritBox. In the UK, the complete series is viewable on BritBox, with the Special Edition available on Amazon Prime Video.
 On Rotten Tomatoes, the show has a 67% approval rating based on 6 reviews.