Members have selected local councillor Cara Hilton, 38, to fight the by-election, on Thursday October 24.
Walker, convicted of 23 domestic abuse charges last month, submitted his resignation to the Scottish Parliament last weekend.
Ms Hilton, councillor for Dunfermline South on Fife Council, said: "As someone living in the constituency, I know the priorities and needs of the hard-working families in Dunfermline.
"We need more jobs, we need our economy to improve, we need more of our young people in work. Instead, we have an SNP Government that is more interested in the referendum than standing up for the people of Dunfermline.
"Dunfermline needs an MSP who will work their socks off for this constituency and who will go to Parliament and put Dunfermline first, not the constitution and the referendum next year.
"I look forward to the campaign ahead and to speaking to thousands of local people who are so desperate for an MSP who will move us on from the disgrace of Bill Walker and who will fight for what we need here in Dunfermline."
Walker, 71, of Alloa in Clackmannanshire, was found guilty following a trial at Edinburgh Sheriff Court last month but initially refused to resign his seat.
The former SNP MSP, who was ejected from the party when the claims surfaced, denied the charges. He is due to be sentenced on Friday.
In a resignation statement released on September 7, he said a "media onslaught" had made it impossible for him to continue.