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.
President of the Senate (Australia)
As well as a president, the Senate also elects a Deputy President, whose formal title is Deputy President and Chairman of Committees. Until 1981, the title was just Chairman of Committees; it was changed "to reflect more accurately the nature of the office in practice". The position is not provided for by the constitution, but instead by the Senate's standing orders – it was borrowed more or less directly from the colonial legislative councils. The deputy president's main tasks are to preside over committees of the whole and to serve as presiding officer when the President of the Senate is absent.