Gboyega Akosile, chief press secretary to the governor, announced the appointment on Wednesday on his X page.
Akosile said Egube would replace the late Gboyega Soyannwo, the former deputy chief of staff, who died on May 15 after a brief illness at the age of 55.
Egube was the former commissioner for economic planning and budget in the first term of Sanwo-Olu’s administration.
Egube, who was born on March 5, 1969, is a fellow of the Institute of Credit Administration (FCIA), a member of the Nigerian Institute of Management (AMNIN), a member of the Council for the Regulation of Engineering in Nigeria (COREN), and an honorary senior member of the Chartered Institute of Bankers.