The division was created in 1949 and is named after Woollarawarre Bennelong, an Aboriginal man befriended by the first Governor of New South Wales, Arthur Phillip.

After a single term, McKew was defeated by Liberal candidate John Alexander in 2010, who retained it (not including a short vacancy in 2017) until the 2022 general election.

The seat was vacant from 11 November 2017 when Alexander resigned amid the 2017–18 Australian parliamentary eligibility crisis after confirming he was a dual citizen and therefore ineligible to sit in parliament.

Successive redistributions eliminated Lane Cove and Hunters Hill in the east and incorporated Eastwood, Epping, Carlingford and middle-class Ermington in the north and west.

Secondly, the demographic has changed as well: since the early 1990s, Eastwood and surrounding suburbs have seen an influx of migrants from China, Hong Kong, South Korea and India, who are relatively affluent and conservative, but are sensitive towards political policies on immigration and multiculturalism.

The 2006 redistribution pushed this margin slightly further into Labor territory, due to the inclusion of the predominantly working-class and public housing suburb of Ermington in Bennelong's boundaries.

In the 2007 election, the incumbent Member for Bennelong, then-Prime Minister John Howard, lost the seat to Labor candidate Maxine McKew, after holding it for 33 years.

After the 2004 election, Howard sat on a margin of four percent, placing Bennelong just barely on the edge of seats that would fall to Labor in the event of a uniform swing that delivered it government.

She also conceded that the removal of Kevin Rudd as Prime Minister had been a factor in the party's poor showing, along with the Government's dumping of the emissions trading scheme and a lacklustre national campaign.

Amid the 2017–18 Australian parliamentary eligibility crisis, the trigger for the by-election was the resignation of Liberal incumbent John Alexander effective 11 November 2017.

A few weeks following the increased clarity which came from the judgment of the High Court of Australia sitting as the Court of Disputed Returns on 27 October 2017 further determining dual citizenship ineligibility under Section 44 of the Constitution, Alexander resigned due to a belief that he may have held British citizenship at the time of his nomination and election, meaning he would be ineligible under Section 44 of the Constitution to sit in the Parliament of Australia.

[24] Alexander won the 2017 Bennelong by-election despite an approximate five percent two-party swing away to Labor candidate Kristina Keneally which made the seat marginal.

With a margin of 9.7% from the 2016 election, Alexander competed against high profile neurosurgeon Brian Owler, who formerly chaired the Australian Medical Association and has worked closely with the NSW Government to be the face of a successful anti-speeding campaign for road safety.

Owler's eminent persona was aided by several inflammatory remarks from Alexander, ultimately leading to a 2.8% swing away to Labor, which reduced the Liberal Party's hold on the seat to a margin of 6.9%.