Retail giant Costco has bought a 14-hectare site for a new national warehouse distribution centre in western Sydney.

Estimated to be the size of 20 football fields, the centre is valued at close to $77 million and will create about 1000 jobs, according to The Sydney Morning Herald.

About 730 construction jobs will be created from the project, along with another 210 operational jobs.

The NSW government has approved the warehouse in Kemps Creek, owned by Goodman Group, making it the company's biggest facility in Australia.

Oakdale Industrial Estate is located close to key motorways, with an end value of about $2 billion.

It has also been suggested as possible site for Amazon's larger Australian warehouse.

The new site will be a depot to serve all Costco warehouses nationally, which now total nine.

There are also three other, smaller sites under construction in NSW, Victoria and Western Australia.

The US-based chain sells memberships for $60 per year and members can then buy the company’s low-price products in a wholesale format.