Teresa Gambaro has joined 10 other coalition members in deciding not to contest the next election.
Ms Gambaro announced on Wednesday she would not stand again in her seat of Brisbane, following 17 years in parliament.
The Queensland MP won four elections between 1996 and 2004 but was defeated in Kevin Rudd's landslide win in 2007.
However, she came back in 2010 and held onto her seat in 2013 by a margin of 4.3 per cent.
"The time has come to be available to my family and to pursue other opportunities," she said in a statement.
She paid tribute to Prime Minister Malcolm Turnbull as having an "exciting vision" for the country.
Former prime minister Tony Abbott came to Ms Gambaro's rescue last year, heading off a messy Liberal National Party preselection battle in Brisbane.
Her challenger was Trevor Evans, the chief executive of the National Retail Association and a former chief of staff to Peter Dutton, who is now immigration minister.
Comment was being sought from Mr Evans, an economist and lawyer, on whether he will again contest preselection.
Queensland Opposition Leader Lawrence Springborg on Wednesday thanked Ms Gambaro for her "great service" to the LNP.
He refused to say whether he'd support former premier Campbell Newman seeking preselection for her electorate after he lost his own state seat of Ashgrove last year.
"I'm not even speculating because we don't even know who's going to stand in a place like that," Mr Springborg said.
Mr Newman was Brisbane's lord mayor before he was catapulted into the LNP leadership, becoming the only MP in Queensland's history to be premier in their first term.
