The other three are in Mudgee, however, one of these cases had not actually been in the local community recently.
A case has also been detected in Bourke, and will be included in tomorrow's numbers.
NSW member for Dubbo Dugald Saunders explained that this third case is actually a person in Sydney, but whose address is in Mudgee, so the case is counted there.
Mr Saunders also clarified that because of its regional location, people in Dubbo are allowed to cross into other local government areas for essentials.
"There is no kilometre requirement, there is no requirement to stay absolutely within your local government area.
"If you're in a regional area and your closest shop is five kilometres across another council border, that is fine, do it, do it sensibly," Mr Saunders said.
"We don't want you driving an hour and a half out of your way to stay within your local government area."
One of the largest employers in Dubbo, Fletcher Abbatoir, is closing for the week.
There have not been any cases detected there, and meat workers and abattoirs are an essential service, but it is reassessing its processes to keep everyone safe.
The Dubbo District Athletics Carnival has been identified as an exposure event and students and staff from across the region have been identified as close and casual contacts.
There has also been an active case confirmed in Bourke, west of Walgett, Mr Saunders said.
NSW Health detected fragments of the virus in the sewage in Bourke last week.
The case will be included in tomorrow's figures.