[1][2] Philomena Mwilu was born on 15 April 1957 in the present day Makueni County, Kaiti division, Kilala location.

Philomena Mwilu is a spouse to Amos Wako, former attorney general and senator for Busia County She studied at Alliance Girls High School.

[citation needed] Justice Philomena Mbete Mwilu's long legal career spans over 35 years.

[1][3] In October 2016, she was nominated to take the position of Deputy Chief Justice of Kenya, replacing Kalpana Rawal, who had attained the mandatory retirement age of 70.

[citation needed] A day before the hearing, her official car had been shot at while driving through traffic, with her driver sustaining gunshot wounds.

[13] A week later, a petition seeking her removal from office was lodged with the Judicial Service Commission on which she sits as a representative of the Supreme Court.

While Mwilu started acting as the Chief Justice on 13 December 2020 when Maraga went on terminal leave ahead of his retirement,[16] the final official hand over of the instruments of power took place on 11 January 2021.