The 1918 Swan by-election was a by-election for the Division of Swan in the Australian House of Representatives, following the death of the sitting member Sir John Forrest.
 Held on 26 October 1918, the by-election led to the election of the youngest person to be elected until 2010 to the Parliament of Australia, Edwin Corboy.
 It saw the conservative vote split between the Country Party and the Nationalist Party, which directly prompted the introduction of preferential voting in Australia.
A by-election was held for the Australian House of Representatives seat of Mayo, located in Adelaide, South Australia, on 6 September 2008, following the retirement of Liberal Party MP and former Liberal leader Alexander Downer.
 The by-election was held on the same day as the Lyne by-election, and the Western Australian state election.
A by-election was held for the Australian House of Representatives electorate of Darling Downs in Queensland on 14 September 1901, a Saturday.
 It was triggered by the death of William Henry Groom on 8 August 1901.
 It was the first by-election of the Australian parliament since Federation.
 The writ for the by-election was issued on 13 August, nominations for candidates closed on 27 August.
The Division of Grayndler is an Australian electoral division in the state of New South Wales.
 The division was created in 1949 and is named for Edward Grayndler (1867–1943), a Member of the New South Wales Legislative Council from 1921 to 1934 and 1936 to 1943, and General Secretary of the Australian Workers' Union from 1912 to 1941.
A by-election was held for the Australian House of Representatives seat of Bradfield on 5 December 2009.
 This was triggered as a result of the resignation of former minister and ex-Liberal Party leader Brendan Nelson.
 The by-election was held on the same day as the Higgins by-election.
The Norwood state by-election, 1980 was a by-election held on 16 February 1980 for the South Australian House of Assembly seat of Norwood.
 It was triggered when the result in the seat at 1979 state election was overturned by the Court of Disputed Returns.
 Created and first contested at the 1938 state election, the seat had been held by former Premier and Labor MHA Don Dunstan since the 1953 state election until his resignation.
 The subsequent 1979 by-election was won by Labor's Greg Crafter, but he lost to the Liberal Party's Frank Webster at the 1979 state election.
A by-election was held for the Australian House of Representatives seat of Lyne on 6 September 2008.
 This was triggered by the resignation of National Party MP Mark Vaile.
 The by-election was held on the same day as the Mayo by-election, and the Western Australian state election.
A by-election was held for the Australian House of Representatives seat of Melbourne in Victoria on 30 March 1904.
 This was triggered by the Chief Justice of the High Court (sitting as a Court of Disputed Elections) declaring invalid the election of Sir Malcolm McEacharn to the seat in the 1903 federal election.
 The writ for the by-election was issued by the Speaker of the Australian House of Representatives on 15 March 1904.
A by-election was held for the Australian House of Representatives Division of Higgins on 5 December 2009.
 This was triggered by the resignation of former Treasurer and former Liberal Party deputy leader Peter Costello.
 The by-election was held on the same day as the Bradfield by-election.
A by-election was held for the Australian House of Representatives seat of Grayndler on 23 June 1979.
 It was triggered by the death of Labor Party MP Frank Stewart.

Question: Which state held a by-election in 1979 for the Australian House of Representatives?
Answer: New South Wales