Hornsby

Apart from a brief period between 1991 and 1999, the electorate of Hornsby has been in existence since 1927 and has always been held by the Liberal Party or one of its conservative predecessors.

Hornsby's brief abolition came about following the decision of the Greiner government to remove the 10 new seats created by Labor in 1988. The Redistribution Commissioners had to choose which of Hornsby or Ku-ring-gai to abolish. Ku-ring-gai was held by Premier Nick Greiner, resulting in Hornsby being abolished and sitting MP Neil Pickard given the sinecure of Agent-General in London. Pickard's spending habits in London eventually led to him being recalled by the Fahey government, a political distraction the government could have done without.

Greiner was succeeded as MP for Ku-ring-gai by Stephen O'Doherty at a by-election following the Metherell crisis in 1992. He switched seat when Hornsby was revived as an electorate name in 1999. A former journalist best known in politics for his role as shadow Education spokesman, O'Doherty resigned in 2002 after which he continued in the education field as CEO of Christian Schools Australia.

New MP Judy Hopwood won the 2002 by-election, Kerry Chikarovski's last test as Liberal leader. Hopwood's first party room meeting saw a ballot for leader between Chikarovski and John Brogden. Hopwood voted for Brogden who was elected leader by one vote.

Hopwood retired at the 2011 election and a pre-selection dispute saw Hornsby contested by Hornsby Mayor Nick Berman after missing out on pre-selection. The size of the swing to the Liberal Party meant the 2011 election was not a good time for breakaway Liberal candidates, and Hornsby was easily won by endorsed Liberal Matt Kean. He was easily re-elected at the 2015 election.

Coloured tab indicates seat won by a party forming government

Liberal majorities were recorded in all 29 polling places used at the 2015 election. The Liberal two-party preferred vote rose from 58.0% at Brooklyn Public school to 88.9% at the small Glenhaven Public School external booth.