The Gap ward councillor will retire from Brisbane City Council at the end of June, bringing to a close an 18-year career at City Hall.

No byelection will occur because council elections are scheduled for March 2016, meaning the LNP will be able to replace her in July with a candidate of its choosing.

The party began advertising for a replacement last week, with the successful candidate to be paid a yearly wage upwards of $175,000.

"If you have a passion for your local area and want to work proactively as part of a united team with a vision for a better Brisbane, then we want to hear from you," an ad circulated by the party says.

Cr Knapp, who turns 70 this year, said she loved her tenure at the council but was looking forward to a life away from City Hall.

"It's been a fabulous time to deliver at the level which I think is the most effective level of government - local government." she said.

"You deal with everyday issues, you can see where you can make a difference and people can see where you make a difference."

Cr Knapp said her retirement would consist of two days a week volunteering for not-for-profit organisations Hear and Say and AEIOU.

"I'm going to play bridge with my girlfriends...look after my grandchildren, join a book club, do nothing one day a week and generally be an active busybody," she said.

She said the highlight on council was her involvement with the Save Our Waterways Now group, which works to restore creeks and waterways in the Enoggera, Ithaca and Fish creeks.

Cr Knapp also praised former premier and lord mayor Campbell Newman. LNP councillors were reluctant to even say Mr Newman's name in council chambers after the shock state election loss, however three weeks later Cr Knapp delivered a 10-minute speech about his legacy.

"Half the policies we're delivering are from Campbell's time," Cr Knapp told Fairfax Media. "We do continue to recognise the programs that he instituted when he came in as mayor."