In NSW, Belmont North, Charlestown, Toronto, Carramar, Castle Hill, Holsworthy, Liverpool and Wetherill Park will be the first to be upgraded.
Lyndhurst and Narre Warren in Victoria will get fibre as will Osborne in South Australia.
In Queensland, Acacia Ridge, Browns Plains, Eight Mile and Oxenford are the first areas selected while Cannington and Double View in Western Australia will also get fibre.
The company said in a statement on Tuesday that its upgrade would pass about 100,000 homes in FttN areas. By the end of 2023, about two million homes in all would be passed.
Progress is also being made on upgrading the HFC network, with forecasts that the end of 2021 most users on this technology will be able to obtain download speeds of between 500Mbps and up to 1Gbps.
NBN Co chief executive Stephen Rue said: "We are investing now and will be working hard in suburbs and towns throughout Australia over the next three years to make the nbn ready for the high-speed broadband needs and data demands of the future.
“More than 72% of our fixed line network is already capable of supporting wholesale download speeds of 100Mbps or faster, and new demand for higher speed services is emerging quickly as customers realise the social, economic and lifestyle benefits that fast broadband can deliver.
“We have connected more than 950,000 premises to the NBN network this year alone, and there has been increasing interest from customers connecting to the NBN for the first time for plans offering download speeds of around 100Mbps or better.
“Throughout 2020, as people have worked, studied and increasingly entertained themselves at home, approximately 55,000 customers have chosen to upgrade via their Internet provider to plans offering download speeds of around 100Mbps or better.
“We see this demand for higher speed broadband services accelerating in the years ahead as more people connect more devices within their homes, and we continue to automate our homes, which inevitably requires faster download and upload speeds and greater capacity to be built into the network.”