Ms Smith worked for another Norfolk MP, former education secretary Gillian Shephard
When former Norwich North MP Ian Gibson made the surprise announcement he was quitting in June, Chloe Smith already had a head start on her rivals for the job.
The Conservative candidate had been selected some 18 months before - while Labour had not been anticipating having to choose a new candidate at all.
But Labour's decision to bar Dr Gibson from standing again over his expenses claims - resented by many in his local party with whom he had been popular, boosted Ms Smith's chances from outsider to favourite.
Her party poured resources into the campaign - with a succession of shadow cabinet ministers paying visits to the Norfolk constituency, party leader David Cameron made six visits himself.
Ms Smith describes herself as a "Norfolk girl through and through" - having lived in the area since she was three and having been a pupil at a comprehensive in the county. She is now a school governor there.
She flags up her experience as a management consultant for Deloitte on her website, saying it has given her "a lot of valuable experience".
But the Conservatives confirm she has been on secondment to the party's central office - she describes her work there as bringing her business skills to help the party "draw up detailed plans to put our policies into practice".
And in a by-election overshadowed by the MPs' expenses row, her Lib Dem rivals accused her of playing down her links with Tory frontbencher James Clappison, who paid back £3,100 claimed for gardening. The official register of MPs' interests lists her as one of his staff.
She has also had Westminster connections for some time - saying on her website she "got into politics when I left school" by working, in her Gap year, for Gillian Shephard, the former Conservative education secretary whom she describes as a "real mentor". She also worked for former Conservative vice chairman Bernard Jenkin.
When the 27-year-old officially takes her seat as the new Conservative MP for Norwich North after the summer recess, she will be the youngest in the House of Commons - two years younger than the previous "baby of the House", Lib Dem Jo Swinson.
Her response to those who suggest she is too young: "If you're good enough, you're old enough."
Shadow cabinet minster Theresa May, who ran her by-election campaign, said her age could be a benefit, following the expenses row.
"As a young woman I think she shows a different approach to politics and a fresh face for politics, and I think that's what voters want."