Growing up in a cultural vacuum can have its advantages. Removed from standard influences and regurgitated clichés, you can develop a unique style all your own. Joanna Neary was born and raised in Cornwall, hundreds of miles from the comedy hubs of London and Edinburgh. ‘There was no stand-up really, just Jethro,’ laughs Neary namechecking the West Country’s hirsute joker. ‘The only comedy I knew about was Joyce Grenfell and I loved all the Ealing comedies, Hancock, Margaret Rutherford, Irene Handl, Patricia Hayes and Alastair Sim.’

So Neary drifted into comedy almost by accident. ‘I did performing arts at college and you had to do a show at the end of each term. I wanted people to cry and laugh but I made people laugh more than anything,’ she explains. ‘I was 16 when I first put on a show to all my tutors, and I was so nervous that I spoke in a northern accent through the whole thing. My pyjamas caught fire because I was smoking a cigarette while I was giving a monologue in a haze of fear. And that northern accent thing was just because I had watched so much Victoria Wood.’

Having developed a character-led theatre show, she decided on a whim to put it in the comedy section of the Fringe brochure. ‘Suddenly I was selling out, with almost the exact same stuff I was doing in theatre.’ This small shift of focus instantly connected with audiences and Neary picked up a Perrier Best Newcomer nomination in 2004. Since then she’s made regular appearances on TV and radio, popping up in Miranda, Armando Lannucci’s Time Trumpet, Ideal with Johnny Vegas, Skins and That Mitchell and Webb Look.

Other Fringe shows have featured a cavalcade of offbeat characters, but this year’s affair is a first for Neary, as she has built an entire hour around a single character. ‘Celia Jesson is based on Laura Jesson in Brief Encounter: it’s not based on [actress] Celia Johnson but on her character.’ She’s a woman out of time who somehow finds herself on stage in Edinburgh. ‘She’s not a natural entertainer, more of an ordinary woman, a repressed housewife from the 1940s. It’s been fun writing a show about a very limited person while making it as funny as possible.’

After filming an unaired pilot for the BBC as Celia, Neary has worked out a full backstory for her comedic creation. ‘She’s my favourite character and I’ve got an incredible amount of material for her that has never seen the light of day. Not much of it ended up in the show but it was nice to have a starting point. Because I’ve done a pilot, her whole world has been fleshed out – her friends, her husband – and I got a chance to interview celebrities in character. This is the first time that I’ll be interacting with the audience, so it’s quite a departure.’

As the show’s title (Faceful of Issues) suggests, Celia will be tackling some of the modern world’s biggest dilemmas including technology, Britpop, burlesque, coach trips, BuzzFeed, Facebook, post offices, bankers and the demise of jumble sales. Don’t worry if you think it all sounds a bit cosy, as Neary has a trick up her sleeve. ‘There’s someone else in the show. Martin is a heavy metaller who plays all the jingles. He’s the only other person in the village who’s agreed to do the show,’ adds Neary. ‘Everything I’ve mentioned is very twee but I really love very dark, very rude humour, and having this other character means I can get a bit of bite into the show. I didn’t want an hour of sweetness.’

Joanna Neary: Faceful of Issues, Assembly Rooms, 0844 693 3008, 7–30 Aug (not 17), 7.45pm, £10 (£9). Preview 5 Aug, £9 (£8)