Josie Jarosz is not seeking re-election in the Pudsey ward and Louisa Cunningham has been chosen by town’s Labour branch to stand in May.
Coun Jarosz has served the ward since September 1993, having first been picked in a by-election following the death of Coun Ann Hickinson.
She said: “I have a growing family of grandchildren and great grandchildren and I want to be a part of their lives.
“The duties of a councillor are getting more time consuming with the effort involved in trying to mitigate the damaging effect that austerity is having on public services.”
Coun Jarosz, whose ambition has been to “ensure that the voices of residents are heard and acted upon,” added that she will miss working with ward colleagues Coun Richard Lewis and Coun Mick Coulson. During her time she has set up residents’ forums in Tyersal, Pudsey and Swinnow.
Coun Jarosz has also campaigned for a dedicated Leeds Children’s Hospital and hopes to discuss plans with fellow councillors before retiring.