Gilleland will work up to 32 hours a week for period not extending six months, but that could be extended, according to Boeder.
“She has a very good reputation,” he said.
Gilleland served as Middletown's city manager from 2008 until her retirement in June 2014.
Gilleland was named to the position after Germantown city council on Jan. 4 accepted the resignation of city manager Annie Sizemore, effective immediately.
Sizemore was city manager for six years, but had previously worked for the city in another role.
In the next few weeks, the city will advertise for a permanent position, Boeder said.