The star was best known for hit sitcom The Royle Family and the riotous chat show The Mrs Merton Show, which both won a string of awards.
Aherne, who more recently narrated Channel 4 show Gogglebox, which was also a success, had been battling lung cancer and had previously been treated for bladder and eye cancer.
Tributes poured in for the star, with Royle Family co-star Sue Johnston saying: “I am devastated at her passing and I am numb with grief.”
BBC director general Lord Hall said: “She was a brilliant, award winning comedy writer and performer, much loved by audiences - especially for The Royle Family and Mrs Merton and for her wonderful voicing of many shows. Our thoughts are with her family and friends.”
Ralf Little, who starred as Antony Royle, brother to Aherne’s Denise in The Royle Family, tweeted: “Sorry for silence - I just... don’t know what to say. What a sad, sad day. We’ve lost another one of our best.
“A character. A legend. A boss. A sister, real and (for me) fake. A boss. A writer. An actor. A genius. A friend. Big, big heart. Goodbye. X”
Aherne gained public attention as the Checkout Girl in The Fast Show. But she became a household name as straight-talking blue-rinse granny Mrs Merton in The Mrs Merton Show, which first aired on BBC Two in 1995 and won the best talk show Bafta in 1997.
The character began life as next-door neighbour to another northern comedy creation, Frank Sidebottom, and appeared on several of his record albums.
Mrs Merton took flight in her own right after a series of radio appearances with the BBC’s Martin Kelner, which led to a television pilot shot in a small studio at the newly-built Meadowhall shopping mall in Sheffield.
David Behrens, digital editor of The Yorkshire Post, who produced the pilot, said: “She was a natural in front of the cameras and assumed the mantle of an old lady as effortlessly as putting on a hat.
“But before the character caught on, it polarised opinion. At least one TV executive thought the idea of a young woman playing an old lady was fundamentally unfunny.”
The Royle Family was born after Aherne and friend Craig Cash, who played gormless Dave Best in the show, threw themselves into their work after a suicide attempt, which she described as her lowest ebb.
It is considered to be a classic British sitcom, despite the unusual format of a working class family sitting in a living room.
The BBC show was the toast of the 1999 British Comedy Awards, scooping four trophies including best actress for Aherne.
It went on to take home the best sitcom Bafta in 2000 and 2007.
Aherne was nominated for Baftas for her performance in both shows, as well as her directing of The Royle Family in 2001.
Aherne’s death was announced by her publicist Neil Reading, who said she died on Saturday at her home in Timperley, Greater Manchester.
The star, who had been a smoker, struggled with health problems for years.
Born to Irish immigrant parents in London before being raised in Manchester, she was diagnosed with a rare cancer of the retina as a child - like her older brother Patrick.
She was sent to Lourdes in search of a miracle cure but was left with severely impaired sight in one eye.
She later fought depression and drink problems - giving a rambling and slurred acceptance speech at the British Comedy Awards in 1996 after being named best female performer.
She spent time in the Priory clinic following a suicide attempt, before moving to Australia to avoid the glare of publicity.
The star also had a string of failed relationships - her marriage to former New Order guitarist Peter Hook ended and she began a romance with TV researcher Matt Bowers.
They split, but she was devastated when he died of cancer at the age of 28.
She once admitted alcohol was an attempt to block out her problems.
Other stars paid tribute to Aherne and her talents.
Coronation Street star Andrew Whyment, who starred as Darren in The Royle Family, fondly remembered their time together.
He wrote: “So sad 2 hear the passing of Caroline Aherne it was a privilege to have worked with her on the Royle Family very talented woman indeed RIP X.”