Norden wrote scripts for Hollywood movies. He also presented television programmes on ITV for many years, including the nostalgia quiz Looks Familiar and blooper shows It'll be Alright on the Night and Denis Norden's Laughter File. He retired in 2006.

Norden was born in Mare Street, Hackney, East London, and educated at the City of London School where he was a contemporary of Kingsley Amis. He "was considered to have a fine academic brain" and was well regarded by his peers.

Upon leaving school he worked as a stagehand, moved into cinema management by the age of 17 and organised variety shows. His writing career began in the Royal Air Force during World War II for troop shows following which, he wrote material for comedian Dick Bentley, before meeting Frank Muir, who wrote for Jimmy Edwards in 1947.

Their first joint venture was the radio show Take It From Here, which they scripted from 1948 to 1959. They went on to write many successful radio and television scripts, including Whack-O! (1956–60) and three series of Faces of Jim (1961–63), both as vehicles for Jimmy Edwards. They also wrote the satirical sketch Balham, Gateway to the South for the BBC Third Programme. The sketch, which had originally been broadcast in 1948 as part of a comedy series called The Third Division and which featured actor Robert Beatty, was later famously performed by Peter Sellers on his 1959 LP – The Best of Sellers. In 1964, their writing partnership broke up, as Muir moved into management with the BBC. Over the next several years, Norden, who had long had a fascination with Hollywood, wrote the scripts for several films, including Buona Sera, Mrs. Campbell and The Bliss of Mrs. Blossom. While no longer writing with Muir, they regularly appeared together on panel shows My Word! (1956–90) and My Music (1966–93), first on radio then TV. Norden also hosted an ITV nostalgia quiz, Looks Familiar.

In 1965, Norden wrote, narrated and starred in a featurette jointly made by the James Bond producers and The Ford Motor Company. The colour short, entitled "A Child's Guide to Blowing up a Motor Car", went behind the scenes of an exploding car stunt being filmed for Thunderball. Norden takes a young relative on a day out to a movie set, where they meet several stars and production team members, but not Sean Connery. Lost for many years, it is now available on the 'Ultimate Edition' DVD of Thunderball, as released in late 2006.

Denis' daughter Maggie was a presenter on London's Capital Radio in its earlier days and she presented the Sunday afternoon programme "Hullabaloo".

Norden was also later well-known to television audiences for his ITV shows: Looks Familiar, It'll be Alright on the Night and Denis Norden's Laughter File.

It'll be Alright on the Night, first broadcast in 1977, consisted of out-takes from film and television linked by witty comments. Much of the material from the early episodes was used on Dick Clark's "Bloopers" specials which aired on NBC a few years later. A couple of mid-1980s editions featured several home video clips: with the increasing private ownership of domestic camcorders were spun off into the long-running You've Been Framed (1990-).

Denis Norden's Laughter File, first broadcast in 1992, showed spoof adverts, real foreign adverts, practical jokes, live television mistakes and other various 'oddities', which Norden said, "tickled our fancies, just when they needed tickling". These items included virtually everything discovered during research for material suitable for Alright on the Night that was not eligible for that show.

He announced his retirement from his two ongoing ITV shows It'll be Alright on the Night and Denis Norden's Laughter File on 21 April 2006 because of his age (84) and also because of poor health.