Planer was born in Westminster, London. He was educated at King's House School and Westminster School and then briefly studied at the University of Sussex before leaving to become an actor.
A founding member of the London Comedy Store and original member of The Comic Strip – pioneers of the alternative comedy movement in the United Kingdom. Planer appeared with Peter Richardson as part of the double act "The Outer Limits". Planer and Richardson also wrote the That's Life! parody on Not the Nine O'Clock News. Over the next 20 years he went on to star in film, theatre and television. With Christopher Douglas, he created the spoof actor character "Nicholas Craig", who appears in book, radio, TV and articles as well as live; most recently at the Royal Festival Hall, London, in Stewart Lee's At Last the 1984 show. Planer is also the author of several books, plays, radio plays, and TV scripts as well as a small volume of poetry. He was awarded an Honorary Doctor of Arts degree from Edinburgh Napier University in June 2011.
Planer is best known for his role as Neil, the hippie housemate in the cult BBC comedy The Young Ones, which ran from 1982 to 1984.
He has starred in The Comic Strip Presents... series of short films, broadcast from 1983 onwards, in the guise of various strange outsiders. In 2011, to critical acclaim, he played Peter Mandelson in The Hunt for Tony Blair.
In 2007, he appeared on a BBC 4 programme in the guise of "Nicholas Craig", interviewed by Mark Lawson. In 2010 he guest starred in the Agatha Christie's Marple episode "The Pale Horse" In 2003, he played Professor Dumbledore in a Harry Potter parody, Harry Potter and the Secret Chamber Pot of Azerbaijan. In 2013, he guest starred in Jonathan Creek for a second time. Other leading roles on TV include Shine on Harvey Moon, Filthy, Rich and Catflap, The Grimleys, King and Castle, Bonjour La Classe and Roll Over Beethoven. He also starred in Michael Palin's Number 27, Simon Gray's Two Lumps of Ice, Emma Tennant's Frankenstein's Baby and Blackeyes by Dennis Potter.
Planer's guest appearances include programmes such as The Bill, French and Saunders, Jonathan Creek, Blackadder III, The Last Detective, the Paul Merton Show, the Lenny Henry Show and Gary Wilmot's Songs from the Shows. He also made a guest appearance in an episode of This is Jinsy entitled "Nameworm". He has appeared in Episodes as Matt le Blanc's lawyer; and in the BBC series Boomers.
His first break in the theatre was understudying David Essex as Che Guevara in the original West End run of Evita. Planer was in the original London cast of Chicago, as Amos Hart. He was a member of the original West End cast of Ben Elton's Queen musical We Will Rock You as Pop.
In 1990, he replaced Michael Gambon in Alan Ayckbourn's Man of the Moment in the West End. Leading roles followed in other productions at the Bush Theatre, the Lyric Theatre, the Traverse, the Young Vic, the West Yorkshire Playhouse, Regent's Park Open-Air Theatre, Chichester Festival Theatre, Plymouth Drum and the Hampstead Theatre.
From 10–15 July 2006 he played the part of the narrator in The Rocky Horror Show, taking on the role in Manchester and Bromley. He then starred as The Wizard in the original West End production of Wicked alongside Idina Menzel. The show opened at the Apollo Victoria Theatre on 27 September 2006. Planer ended his run on 7 June 2008 and was replaced by Desmond Barrit.
He took over the role of Wilbur from Ian Talbot in the West End production of Hairspray on 2 February 2009.
In 2010, Planer returned to the role of the Narrator in the UK Tour of The Rocky Horror Show, playing in Cambridge and Northampton, before also reprising the role of Wilbur in Manchester and Leeds. He also featured in Doctor Who: Live touring the UK, as Vorgenson The Inter-Galactic Showman, before appearing in Pantomime as Captain Hook at the Lyceum Theatre in Sheffield.
Planer went on to star as Grandpa Joe in the original production of Charlie and the Chocolate Factory, which opened in London's West End in 2013.
Planer has appeared in a number of films: Flood, Virgin Territory, Bright Young Things, Hogfather, The Colour of Magic, Wind in the Willows, Land Girls, Clockwork Mice, Carry on Columbus, Brazil, The Supergrass, I Give It a Year, The Apple Picker and Yellowbeard.
Planer played Den Dennis, one of the four members of the 1980s spoof rock band, Bad News who made two albums produced by Brian May. They also performed at the Hammersmith Apollo as well as the Donington and Reading Rock Festivals.
As Neil from The Young Ones, Planer gained a number two hit single in 1984 in the form of "Hole in My Shoe", (originally a hit for 1960s band Traffic). A cover of Tomorrow's "My White Bicycle" was a less successful follow up, only reaching No.97 in the charts. After that, an album was produced, entitled Neil's Heavy Concept Album. Planer also took Neil's stage act on the road in that year as Neil in the "Bad Karma in The UK" tour. This culminated in a month-long run at St. Mary's Hall at the Edinburgh Festival Fringe. The Young Ones also appeared on Cliff Richard's 1986 charity rerecording of "Living Doll", which spent three weeks at number one in the UK. He has a silver and a gold disc and has a Brit award from his musical career. In 2015' he started a new music project called Rainsmoke with Chris Wade (Dodson and Fogg) and Roger Planer.
In 2017 he recorded two songs for the album Wit & Whimsy - Songs by Alexander S. Bermange (one solo and one featuring all of the album's 23 artists), which reached No. 1 in the iTunes comedy album chart.
Planer is the main reader for the audiobook editions of many of Terry Pratchett's Discworld novels. He also appeared in the television adaptations of both Terry Pratchett's Hogfather and The Colour of Magic, and performed as a voice artist in the games Discworld 2 and Discworld Noir. Discworld Audiobooks narrated by Planer include (with number in parentheses indicating order of the book in the Discworld series):The Colour of Magic (1)
The Light Fantastic (2)
Wyrd Sisters (6)
Guards! Guards! (8)
Moving Pictures (10)
Reaper Man (11)
Witches Abroad (12)
Small Gods (13)
Lords and Ladies (14)
Men at Arms (15)
Soul Music (16)
Interesting Times (17)
Feet of Clay (19)
The Last Continent (22)
Carpe Jugulum (23)
Other voice roles include the narrator of Grizzly Tales for Gruesome Kids, the title character of Romuald the Reindeer, and Dr. Marmalade in an episode of SpongeBob SquarePants (alongside Young Ones co-stars Christopher Ryan and Rik Mayall). Planer has also been the narrator of many of BBC Four's Britannia series of documentaries, including Prog Rock Britannia, Blues Britannia and Heavy Metal Britannia. In addition he voiced Frodo in The Adventures of Tom Bombadil from the 1992 radio series Tales from the Perilous Realm. He was a narrator in a direct-to-video version of Val Biro's Gumdrop book series in 1994. He also narrated two short surreal monologues on the album In A Strange Slumber, by Dodson and Fogg, Chris Wade's progressive folk rock project.
Planer's father, George, founded Planer Group PLC, a high-tech medical firm. His mother, Lesley, was a speech therapist.
He has two sons from previous marriages: Stanley, with Anna Lea (married 19 August 1988–95); and Harvey, with Frankie Park (married April 1999 – 2003).
He is arguably best known in Britain for his work in television comedy and satire, including:Boom Boom...Out Go The Lights (1980)
Shine on Harvey Moon (1982)
The Young Ones (12 episodes) (1982–84)
The Comic Strip Presents… (25 episodes) (1983–2012)
Roll Over Beethoven (9 episodes) (1985)
King and Castle (12 episodes) (1986–88)
Filthy Rich & Catflap (6 episodes) (1987)
Blackeyes by Dennis Potter (1989)
Frankenstein's Baby (1990)
Nicholas Craig – The Naked Actor (1990)
Nicholas Craig's Interview Masterclass (1990)
Oh, No! Not THEM! (1990)
Nicholas Craig's Masterpiece Theatre (1992)
The Nicholas Craig Masterclass (1992)
Carry On Columbus (1992)
The Magic Roundabout (English adaptation and narrator on previously unseen episodes)
Bonjour la Classe (1993)
Sherlock Holmes (1993)
Let's Get Divorced (1994)
Wake Up! With Libby And Jonathan (1994)
Blackadder the Third
French & Saunders
The Grimleys (1997–2001)
Grizzly Tales for Gruesome Kids (1999–2007)
Terry Pratchett's Hogfather (2006)
Terry Pratchett's The Colour of Magic (2008)
He has published several books including the novels The Right Man (2000) (ISBN 0-09-927227-X) and Faking It (2003) (ISBN 0-09-940986-0). Planer also wrote A Good Enough Dad (1992) (ISBN 0-09-929661-6) after his first son was born, talking about coping with becoming a father."Hole in My Shoe" (1984)
Neil's Heavy Concept Album (1984)
"Living Doll" (1986)
"Rough with the Smooth" (1986)
Bad News (1987)
Bad News Bootleg (1988)
Bad News The Cash In Compilation (1992)
The Last Night (1993)
Chicago cast recording (1995)
The Dreaded Lurgie (1998)
Three Men in a Boat (1999)
Adrian Mole the Cappuccino Years (2000)
There was also a soundtrack to The Grimleys (2000), Planer's character appearing on the album.
We Will Rock You (The Original London Cast Recording) (2002)
The Robe of Skulls (2008)
Charlie and the Chocolate Factory (The Original London Cast Recording) (2013)
Dodson and Fogg – In A Strange Slumber (2014)