The 1919 Australian Senate election was held on 13 December 1919 to elect 19 of the 36 senators in the Australian Senate as part of the 1919 federal election. Each state elected three senators to serve a six-year term beginning on 1 July 1920, except for Tasmania, who elected an extra senator to fill a casual vacancy.[1]
Following the resignation of Labor senator James Long in December 1918, Nationalist Edward Mulcahy was appointed by the Parliament of Tasmania to fill the casual vacancy.[14] As a result, Tasmania elected four senators, with the fourth senator elected sitting the remainder of Long's term ending on 30 June 1920.[15]