As originally created, it covered the outer northwestern suburbs of Sydney, though that city's dramatic growth made it an entirely urban seat after World War II. For most of the first seven decades after Federation, it included a large amount of conservative-leaning territory that usually swamped Parramatta itself, which has historically been a working-class area. As a result, the seat was held by the Liberals and their predecessors for all but one term from Federation until 1977. A redistribution ahead of the 1977 election split Parramatta almost in half. Most of the wealthier eastern half became the comfortably safe Liberal seat of Dundas. Most of the western half, including the bulk of the Parramatta LGA, became the core of a marginal Labor seat that retained the Parramatta name, as per Australian Electoral Commission guidelines that require the names of original Federation electorates to be preserved where possible. However, the reconfigured Parramatta was anchored in traditionally pro-Labor territory in western Sydney. Parramatta's Liberal incumbent, Phillip Ruddock, opted to follow most of his base into Dundas, allowing his 1975 challenger, John Brown to become only the second Labor member ever to win Parramatta. Since then, it has been located between Labor's traditional heartland of western Sydney and the traditional Liberal stronghold of the North Shore. As a result, whenever the seat is redistributed, a shift of a few kilometres to the west or east can radically alter its political landscape. Most recently, the 2006 redistribution shifted Parramatta from marginally Labor to notionally marginally Liberal. Nevertheless, as was widely expected at the 2007 federal election, the incumbent Labor member, Julie Owens, held the seat ahead of Liberal candidate Colin Robinson, a member of the Electrical Trades Union, with an increased majority. Owens has subsequently been re-elected at the 2010, 2013, 2016 elections, and 2019. Owens' win in the seat in 2004 marked the first time that the Liberals and their predecessors had won government without also winning Parramatta. Prominent members of Parramatta over the years have included Joseph Cook, a former Prime Minister; Garfield Barwick and Nigel Bowen, both of whom served as Attorney-General before moving to senior judicial position, Barwick as Chief Justice of the High Court. Ruddock, a former Attorney-General and Immigration Minister also represented the seat ; as did Brown, a former Sports Minister.
