Leader of the Government in the Senate (Australia)
The current Leader of the Government in the Senate is Mathias Cormann. The current Deputy Leader of the Government in the Senate is Simon Birmingham, who was appointed on the same date following the resignation of Mitch Fifield.
Australian head of state dispute
A comprehensive guide (by David Hamer) to Australian government published by the Australian Senate, declares that Australia has two heads of state in the monarch, who performs a symbolic role, and the Governor-General, who is "the constitutional head of state."