Ms Stitt, a former trade union leader and now a state upper house member, has been sworn in as workplace safety minister and early childhood minister.

"I know Ingrid Stitt will be an outstanding contributor to our cabinet, bringing her dedication to delivering safer workplaces and overseeing those critical early years for our youngest Victorians," the premier said in a statement on Tuesday.

The reshuffle follows Ms Mikakos' resignation on Saturday as health minister and from the cabinet.

She said she could no longer stay as she strongly disagreed with elements of the premier's evidence to the hotel quarantine inquiry.

Deputy Premier and Education Minister James Merlino will take on the mental health portfolio left by new Health Minister Martin Foley.

Government Services Minister Danny Pearson picks up creative industries, while state member for Western Victoria Gayle Tierney has been elevated to deputy leader of the Legislative Council.

Australian Associated Press