The blunder in Woodfield Way, Balby shows a sign on the left of the road with the limit set at 40mph - while on the right hand side, a sign shows the limit at 30mph.
To add to the confusion, a sign painted on the road leading into the new housing estate, puts the limit at 30mph.
Becky Fowler, took the picture and said: "It's at Plantation, where you go left to Tesco, the signs are there when you go straight on into the housing estate."
It is not clear how long the signs have been in place.
And it is not the first time signs have caused confusion in Doncaster.
Last year, a Sainsbury's petrol station at Edenthorpe came under fire after a sign painted on the road directed drivers towards "petrel" while residents in Penistone Street, Doncaster were left puzzled when signs went up on either side of the street - one as Penistone while the other was spelled Pennistone.
And in 2015, it was revealed how the same 30/40mph blunder had been made on the A6002 in Nottinghamshire.
It is understood the correct sign should be 30mph.
According to the Highway Code, the speed limit of 30mph automatically applies to built up areas and which are identified by the presence of street lights.
We have contacted Doncaster Council for comment.