Skinner joined the Liberal Party and became vice-president of the Cremorne Branch and gained preselection for the seat of North Shore at the 1984 election, and the 1988 election.
However, she was defeated by the sitting independent member, Ted Mack.

When Mack resigned, Skinner again contested North Shore at the ensuing by-election but lost to Robyn Read, an independent candidate; Skinner gained 35 per cent of the primary vote.

At the 1991 state election Skinner did not contest for the seat of North Shore.
Instead, sitting Liberal MP Phillip Smiles ran for the seat, after his own seat of Mosman was abolished in a redistribution.
Although North Shore's demographics suggested it should have been a comfortably safe Liberal seat, Smiles was the first Liberal to win it, ending a decade of representation by independent MPs.

However, by late December 1993, Smiles was forced to resign from Parliament after being convicted of tax evasion.
Skinner subsequently gained Liberal Party preselection for the ensuing by-election.

 On 5 February 1994, Skinner was elected as Member for North Shore with 54 percent of the primary vote and 58 percent of the two-party vote, defeating former independent member Read in a rematch.
She was duly sworn in as a member of the NSW Legislative Assembly.

Skinner has never faced another contest nearly that close in this comfortably safe Liberal seat.
For example, she secured a swing of 13.9 points at the 2011 state election and won 80.3 per cent of the two-party vote.

After the Labor party won the 1995 election, Skinner was appointed to the opposition frontbench and held various shadow portfolios over the next decade.
Under opposition leaders Peter Collins, John Brogden and Peter Debnam, Skinner was Shadow Minister for Health (1995–2003, 2005-2011), Youth Affairs (1995–99, 2002–03), Arts (2003–08), Education and Training (2003–05), School Education (2005), Cancer and Medical Research (2006–07) and Science and Medical Research (2007–08).

Following the 2007 election, Debnam's deputy, Barry O'Farrell, announced he would challenge Debnam's leadership.
When it became apparent that Debnam did not have enough support to fend off O'Farrell's challenge, he resigned, leaving O'Farrell to take the leadership unopposed.
Skinner was elected Deputy Leader, and hence Deputy Leader of the Opposition.
She retained the position of Shadow Minister for Health, which she has held from 7 September 2005 until the 2011 state election when the Coalition gained government.

Following the Coalition's landslide victory in 2011, O'Farrell announced that Skinner would be appointed to the cabinet as Minister for Health and Minister for Medical Research.
When O'Farrell resigned as Premier in April 2014, Skinner opted not to continue as deputy leader under his successor, Mike Baird.
She was succeeded by Gladys Berejiklian.

On 27 January 2017, shortly after Baird resigned and was succeeded by Berejiklian, Skinner announced her intention to resign from politics.
She formally resigned on 20 February 2017.
Skinner joined the Liberal Party and became vice-president of the Cremorne Branch and gained preselection for the seat of North Shore at the 1984 election, and the 1988 election. However, she was defeated by the sitting independent member, Ted Mack.
When Mack resigned, Skinner again contested North Shore at the ensuing by-election but lost to Robyn Read, an independent candidate; Skinner gained 35 per cent of the primary vote.
At the 1991 state election Skinner did not contest for the seat of North Shore. Instead, sitting Liberal MP Phillip Smiles ran for the seat, after his own seat of Mosman was abolished in a redistribution. Although North Shore's demographics suggested it should have been a comfortably safe Liberal seat, Smiles was the first Liberal to win it, ending a decade of representation by independent MPs.
However, by late December 1993, Smiles was forced to resign from Parliament after being convicted of tax evasion. Skinner subsequently gained Liberal Party preselection for the ensuing by-election.
 On 5 February 1994, Skinner was elected as Member for North Shore with 54 percent of the primary vote and 58 percent of the two-party vote, defeating former independent member Read in a rematch. She was duly sworn in as a member of the NSW Legislative Assembly.
Skinner has never faced another contest nearly that close in this comfortably safe Liberal seat. For example, she secured a swing of 13.9 points at the 2011 state election and won 80.3 per cent of the two-party vote.
After the Labor party won the 1995 election, Skinner was appointed to the opposition frontbench and held various shadow portfolios over the next decade. Under opposition leaders Peter Collins, John Brogden and Peter Debnam, Skinner was Shadow Minister for Health (1995–2003, 2005-2011), Youth Affairs (1995–99, 2002–03), Arts (2003–08), Education and Training (2003–05), School Education (2005), Cancer and Medical Research (2006–07) and Science and Medical Research (2007–08).
Following the 2007 election, Debnam's deputy, Barry O'Farrell, announced he would challenge Debnam's leadership. When it became apparent that Debnam did not have enough support to fend off O'Farrell's challenge, he resigned, leaving O'Farrell to take the leadership unopposed. Skinner was elected Deputy Leader, and hence Deputy Leader of the Opposition. She retained the position of Shadow Minister for Health, which she has held from 7 September 2005 until the 2011 state election when the Coalition gained government.
Following the Coalition's landslide victory in 2011, O'Farrell announced that Skinner would be appointed to the cabinet as Minister for Health and Minister for Medical Research. When O'Farrell resigned as Premier in April 2014, Skinner opted not to continue as deputy leader under his successor, Mike Baird. She was succeeded by Gladys Berejiklian.
On 27 January 2017, shortly after Baird resigned and was succeeded by Berejiklian, Skinner announced her intention to resign from politics. She formally resigned on 20 February 2017.
Jillian Skinner