This is a list of appointments to the Australian Senate, which is the upper house of the Parliament of Australia, filling casual vacancies, from the Senate's creation in 1901 until the present day.
Section 15 of the Australian Constitution requires the parliament of the relevant state to choose a replacement.
This is done in a joint sitting of the upper and lower house (except for Queensland, which has a unicameral parliament).
While senators were elected for a six-year term, people appointed to a casual vacancy only held office until the earlier of the next election for the House of Representatives or the Senate, at which the vacancy would be filled by the electors of the relevant state.
Prior to 1980, replacement senators in the ACT or the NT were to be elected in a by-election, though this never occurred.