She'll play Amanda's mother, Felicity, in the upcoming third series on BBC Two.
The mums (and dad) are back to navigate the pitfalls of parenting and the clash of cliques formed at the school gate in Motherland.
Series three sees the gang tackle a nit pandemic, a school trip and Mothers Day which sees Amanda endure lunch with her mum Felicity, played by Joanna Lumley.
Speaking about playing Amanda’s mum in the new series, Joanna said "I have played Lucy’s mother before, in the film Ella Enchanted so it was a special treat to pitch up again as another fairly poisonous parent in Motherland. Although I was only in for a day it was the greatest fun to be with that dangerously talented cast."
Created by Sharon Horgan, Graham Linehan, Helen Serafinowicz and Holly Walsh, the new series has been written by Holly Walsh, Helen Serafinowicz and Barunka O'Shaughnessy with Sharon Horgan as Story Editor.
Motherland returns soon on BBC Two