Construction began three years ago for the $5.3 billion international airport, also known as Nancy-Bird Walton Airport, at Badgerys Creek, 45km from the Sydney CBD, which is due to open in late 2026.
It will be the first airport in NSW with no curfew, allowing flights to operate around the clock, seven days a week.
The proposed flight paths, along with estimated aircraft noise impacts, are available through an online interactive Aircraft Overflight Noise Tool.
People living in Mount Druitt, Penrith, Windsor, Bankstown, Luddenham and Prospect are likely to be the most impacted.
A 20km stretch of land will be subjected to noise levels of about 70 decibels, according to noise assessment modelling.
The suburb of Erskine Park will be particularly hard hit, with up to 49 flights exceeding 70 decibels expected in a single day.
About 25,000 flights are expected to fly in and out of the airport each year.
Transport Minister Catherine King says community information and feedback sessions will be held across Western Sydney and the Blue Mountains in the coming months.
"Communities will be able to find out more information and speak with the flight path design team at these events," she said.
"The Albanese government is committed to balancing the needs of the community, environment, industry and users of the broader greater Sydney airspace, while maintaining safety as a priority, in the design of (the airport's) flight paths."
Labor MP for Macquarie Susan Templeman says numerous flight paths will affect the Blue Mountains and Hawkesbury.
"These are not the same flight paths that were included in the Environmental Impact Statement (EIS) of 2015, which had every incoming flight pass over Blaxland," she said in a statement.
Ms Templeman said many residents will be shocked and upset about planes flying over a pristine and quiet World Heritage area.
"It's the last thing people (and) tourists would want," she said.
The preliminary flight paths were developed according to airspace design principles reflecting community feedback from "proof-of-concept" flight paths released in 2015.
These include minimising flights over residential areas, and reducing the impact on the community of aircraft operations at night.
Business Western Sydney executive director David Borger said the airport and its associated flight paths had been in planning for the past 30 years and no one should be shocked.
"Of course there will be impacts," he told AAP.
"But it nowhere near compares to Sydney (Kingsford Smith) airport."
Mr Borger said the airport has been designed to avoid as much residential noise impact as possible.
"It's a once-in-a-generation opportunity to generate employment and connect Western Sydney with the world," he said.
Western Sydney Leadership Dialogue chief executive Adam Leto said the noise impact on residents will be minimal, and the project has already begun to generate "massive momentum" in terms of jobs and investment.
"In the majority of instances, planes would not be flying directly over the top of homes, they'll be flying over paddocks," he said.
Later this year, the federal government will release a new draft environmental impact statement examining the noise, social and environmental impacts of the flight paths.
The tool is available at: wsiflightpaths.gov.au