Ms Whitefield served three terms at Holyrood representing Airdrie and Shotts before losing her seat to the SNP's Alex Neil in 2011, and becomes the candidate in Falkirk after a prolonged period of turmoil in the constituency party. Her comments after the selection meeting reflected that as she talked about the battle to win back trust in the town after a spate of controversies.
In an all-women shortlist imposed by the party hierarchy amid ballot-rigging allegations, she saw off the challenge of contenders Monica Lennon and Pam Duncan.
Ms Whitefield said: "I am delighted that Labour members in Falkirk have put their faith in me to fight this vital election.
"We have a hard battle ahead in winning back the trust of the people of Falkirk and it is an opportunity we do not take for granted. I am determined that we will do it by fighting on the issues that matter to these communities."
She added: "We have a Tory Government that is doing nothing about the cost of living crisis and an SNP Government that wants to use damaging decisions like the bedroom tax to make an argument for independence rather than protecting people.
"If people put their faith in me, I will always put Falkirk first."
Johann Lamont, Scottish Labour Leader, said: "Karen will be a fantastic candidate and a strong voice for the people of these communities. I look forward to campaigning with Karen."
Sitting MP and former Army officer Eric Joyce had been involved in a string of controversies before he was convicted of assault in a House of Commons bar. He resigned from the party but continues to sit as an independent.
The process of choosing a successor as Labour candidate then erupted into acrimony when one of the candidates, local councillor Linda Gow, complained that the Unite union was signing up new party members in an effort to secure preferred candidate Karie Murphy's selection.
Behind this was said to be the local party chair Stevie Deans, shop steward at the Ineos petrochemical plant at Grangemouth, and when the company sought to discipline him it almost led to the permanent closure of the facility.
Mr Deans and Ms Murphy were initially suspended by Labour but later reinstated as some witnesses who said they had been signed up as party members without their knowledge withdrew their claims.
But in spite of the reinstatement of Mr Deans and Ms Murphy, and the eventual resolution of the Ineos dispute, lasting damage was caused to relations between the party and the union, its biggest donor. Mr Deans has since resigned as local party chairman and been replaced.
The controversy reached Labour leader Ed Miliband, who came under fire for refusing to publish details of the party's inquiry or to open a fresh investigation, defying not just calls from the Conservatives but from senior figures in his own party such as Alistair Darling and Jack Straw.
When Labour's National Executive Council came to impose an all-women list of three for the local party to select from, Linda Gow, who made the original complaint against Unite, was devastated to find herself frozen out.
Labour will hope the selection of Ms Whitefield will help to close the book on a period of civil war within the local party in Falkirk.
Ms Whitefield said last night: "I'll be campaigning for a fairer and more just Scotland.
"I don't think it is right that we have got a Government that would rather reward millionaires than hard-working families.
"I don't think it is right that we have got a Government that is more interested in protecting payday loan companies than regulating them.
"Those are the issues that I will be campaigning on, and I'm sure that the Labour Party will be campaigning with me too.
"If we campaign on those issues Labour will, and can, win the next general election."
l The SNP have picked a co-founder of the Women for Independence group as candidate for the Holyrood by-election for Cowdenbeath on January 23.
Natalie McGarry, 32, was born and raised in Inverkeithing, studied law at Aberdeen University and works for a voluntary organisation.