Dunderdale took over as premier after Danny Williams retired in late 2010.
Dunderdale stepped down as premier on Jan. 24. Until announcing her resignation as MHA on Friday, she had made no public comment since then.
In a news release issued on Friday, Dunderdale said she was grateful to the people of Virginia Waters for their support.
"I am honoured by the support you have shown me throughout the past 10 and a half years since you first elected me, and I am deeply grateful to you for giving me the opportunity," Dunderdale said in the release.
Cathy Bennett, the St. John's businesswoman who ran unsuccessfully for the Liberal leadership in November, has already said she will seek the Liberal nomination in the district in the next provincial election.
She has called on Dunderdale to step down soon so that a byelection can be called.
St. John's councillor Danny Breen said he is "giving some thought" to running as the PC candidate in the pending byelection.
He said he will have more to say next week.
Dunderdale was first elected as an MHA in 2003.