The new Senate, including 12 new Senators, took part in the official ceremony at Parliament House.
Member for Fairfax Clive Palmer was among the guests, watching the three Palmer United Party senators take the oath.
They form part of the record number of 18 crossbenchers, acknowledged by Greens Senator Scott Ludlum.
Addressing the Senate during his bid for Senate president, Senator Ludlum emphasised that crossbenchers were “an important part of the chamber”.
“This is the largest number of crossbenchers there has been in this place,” he said.
“We believe that as part of the increasing diversity of this place, the crossbenchers should put themselves forward… for positions such as this.”
The new Senate now consists of 33 Coalition Senators, 25 Labor, 10 Greens and eight Senators from minor parties.
Senate president elected
Tasmanian Liberal Stephen Parry was elected Senate president in a secret ballot.
Australian Greens' nominee Scott Ludlam won only the 10 votes of his own party, despite urging the crossbenchers to reject the deal for the presidency stitched up between Labor and the coalition.
Under the deal, Labor's Gavin Marshall will be elected deputy president later on Monday.
Senator Parry said he would defend the Senate as being "truly independent" from the executive.
He replaces Labor's John Hogg in the role.
