But residents of border towns like Cobram-Barooga will be able to apply for exemptions to travel for work and essential health services.
NSW Police Commissioner Mick Fuller said the closure would be enforced on the NSW side from Tuesday 11:59pm, and there would be delays getting over the border for the first three days.
"The reality is, in the first 72 hours from midnight Tuesday this week, it will be difficult - not impossible - but difficult to make that crossing," he said.
"There will be delays while we work through who are essential workers."
He said Services NSW would open an online application by tomorrow for people to apply for an exemption.
"We will take a sensible but pragmatic approach to those coming into NSW to ensure we protect the people of NSW," he said.
NSW Premier Gladys Berejiklian said it was a "mammoth task" to monitor the 55 border crossings between Victoria and NSW.
Ms Berejiklian said people who would normally travel across the border "will be restrained" until the permit system is in place.
"We hope that will happen in the next two days," she said.
Victorian Premier Daniel Andrews said movement across the border would be allowed for work or health reasons.
"There will be a facility for people who live on those border communities to be able to travel to and from for the purpose of work, for the purposes of the sort of essential health services they might need," he said.
Mr Andrews said it was a joint decision made by him, the NSW Premier and Prime Minister Scott Morrison on Monday morning.
“All of us agreed the best thing to do would be to close the border,” Mr Andrews said.
Mr Andrews said it would be enforced on the NSW side, which would free up Victorian resources.
“This is one of those things that I think will help us – in broader terms – contain the spread of the virus,” he said.
He apologised for any inconvenience the rule would cause people who have to travel to NSW.
It is not yet clear how long these arrangements will be in place for.
In the last 24 hours, 127 cases of COVID-19 have been diagnosed, and a man in his 90s died from the virus.
There are now 31 people in hospital, with five in intensive care.
EARLIER: The Victoria-NSW border will close from Tuesday night, July 7.
The announcement was made by Victorian Premier Daniel Andrews this morning, following discussion between state premiers about the rising COVID-19 numbers in Victoria.
Border towns such as Cobram and Barooga fall under the bracket of municipalities placed under a permit system, which will allow for travel between states for work and essential services.
“From 11.59 pm tomorrow night, the border with NSW will be closed,” Mr Andrews said.
“There will be a facility for people who live on those border communities to be able to travel to and from for the purposes of work, the purposes of the essential health services they might need.”
NSW Premier Gladys Berejiklian is expected to announce more details at noon.
The closure will be enforced in NSW.