It follows the resignations of the previous board members, who quit after chairman Paul Godfrey was dismissed Thursday.
The interim members are deputy finance minister Steve Orsini, associate deputy finance minister Greg Orencsak, deputy environment minister Gail Beggs, and Lynn Betzner, deputy minister of communications and intergovernmental affairs and associate secretary of the cabinet.
Peter Wallace, secretary of the cabinet, was appointed interim chairman Thursday when Godfrey was fired.
Finance Minister Charles Sousa did not give a reason for Godfrey's dismissal and Godfrey said when he asked he did not get a straight answer.
Godfrey said he believed he and Premier Kathleen Wynne just didn't have the right chemistry.