It happened on the Mossway Roundabout, on the Mosborough A57 bypass near Crystal Peaks, at around 5.30pm this afternoon (Monday, August 31).
According to reports on social media, a car had overturned in the crash.
The AA traffic map is currently showing congestion in the area as the emergency services deal with the incident.
The extent of any injuries is not yet known.
We have contacted South Yorksire Police for more details.