Jade Holden, an IT worker who is also a LibDem candidate in next year's European Parliament election, will contest the seat for the party.
Labour, the SNP and the Conservatives have already announced their candidates for the Holyrood contest, which is being held following the death of Labour MSP Helen Eadie.
Scottish LibDem leader Willie Rennie said: "Jade will make an excellent MSP. She'll work hard, listen and get things sorted at a local and national level."
Ms Holden said: "Working with Willie Rennie I want to get things done for local people. We want improved and expanded childcare, even more cuts to tax for those on low and middle incomes and a Scottish Parliament with more powers but part of the UK.
"The SNP have got the wrong priorities for Scotland. And Labour can't be trusted with the economy."
Mrs Eadie died last month at the age of 66, just days after it emerged she was being treated for cancer. The vote to find her successor will be held on January 23.
Labour has selected Fife Council leader Alex Rowley - who has also worked as constituency manager for ex-prime minster Gordon Brown - as its candidate.
Natalie McGarry, a policy adviser working in the voluntary sector, will contest the seat for the SNP, while the Conservatives have announced local councillor Dave Dempsey as their candidate.