List of longest-serving members of the Australian Senate

The first Senate was elected on 30 March 1901. All the members elected to that First Parliament therefore had equal seniority. It follows that there could not be a "longest-serving Senator" until only one Senator from the First Parliament was still in the House. That occurred on 14 September 1923 with the death of Hon Edward Millen.

Since that date the longest-serving members of the Senate have been:

Rt Hon Sir George Pearce: first elected 30 March 1901, term ended (defeated) 30 June 1938

Between 30 June 1938 and 30 June 1947 Hon Thomas Crawford and Hon Hattil Foll had equal lengths of service, both having been elected on 1 July 1917

Between 30 June 1947 and 30 June 1950 Hon Gordon Brown and Hon Joseph Collings had equal lengths of service, both having been elected on 1 July 1932

Hon Gordon Brown: first elected 1 July 1932, term ended 30 June 1965
Hon Walter Cooper: first elected 17 November 1928, term ended (defeated) 30 June 1932, again elected 1 July 1935, term ended (retired) 30 June 1967

Between 30 June 1967 and 24 May 1971 three Senators had equal lengths of service, having been elected on 1 July 1947

Between 24 May 1971 and 30 June 1971 Albion Hendrickson and Justin O'Byrne had equal lengths of service, having been elected on 1 July 1947

Hon Justin O'Byrne: first elected 1 July 1947, term ended (retired) 30 June 1981
Hon Douglas McClelland: first elected 1 July 1962, term ended (resigned) 23 January 1987

Between 23 January 1987 and 5 June 1987 three Senators had equal lengths of service, having been elected on 1 July 1970

Between 5 June 1987 and 5 June 1987 Hon Peter Durack and Hon Arthur Gietzelt had equal lengths of service, having been elected on 1 July 1970

Hon Peter Durack: first elected 1 July 1970, term expired (retired) 30 June 1993

Between 30 June 1993 and 30 June 1999 Dr Malcolm Colston and Brian Harradine had equal lengths of service, having been elected on 13 December 1975

Brian Harradine: first elected 13 December 1975