Graham Linehan was inspired to create the series after a visit to his home by a PC repair man with questionable interpersonal skills.

Richard Ayoade reprised his role as Moss in the American adaptation of the series. NBC ordered a full season and even began promoting the series for its 2007-2008 season. Although several episodes had been scripted, the chairman for NBC at the time Ben Silverman had the show canceled before filming began as he didn't believe in the show finding success.

The show has garnered an extensive cult following among IT professionals. They've found many aspects of the show true to life. For example, the IT "office" is located in a dingy section of the basement, and is usually filled with a random assortment of equipment scattered about in varying states of repair, as well as the frustration experienced by IT staff in attempting to explain even simple computer concepts, IT-related practical jokes they play on each other and users alike, and the frequent exasperation at having to deal with management that has little (if any) concept as to what the department really does or how much work they perform.

Schedule conflicts with The Mighty Boosh (2003) allowed Noel Fielding to appear in only one episode in the third season. The explanation for his long-term absence was that Richmond (the character he played) got scurvy.

On the UK DVD of The IT Crowd, one of the subtitle options comes up in '1337' or 'leet' speak. 1337, based on the term 'elite', is a language of slang predominantly used by gamers and Internet users, and so fits in with the characters and general humour of The IT Crowd.

It is never revealed what Reynholm Industries makes, though "electronic machines" are hinted at throughout, based on Roy and Moss's remarks to colleagues.

A fifth series was planned but never came to light, the special 'The internet is coming' was made instead.

Channel 4 put the episodes online one week before they were aired on TV.

Graham Linehan's inspiration for Richmond was the wholly incongruous sight of two Goths intently marking up their scorecards on a crazy golf course.

The show's writer, Graham Linehan, makes numerous cameo appearances in many episodes, including a mariachi, a Soviet smoker, and a mystic in the desert.

Moss has a picture of the Flying Spaghetti Monster on his wall.

Christopher Morris (Denholm Reynholm), who plays father to Matt Berry's (Douglas Reynholm's) character, is less than nine years older than Berry.

The exterior shots of Reynholm Industries are News International, Thomas Moore Square London.

Chris O'Dowd (Roy Trenneman) & Katherine Parkinson (Jen Barber) also worked together on episode 2.9, Doc Martin: On the Edge (2006), of Doc Martin (2004), as Jonathan & Pauline Lamb respectively.