The road is shut at the Ruswarp junction for traffic travelling northbound with vehicles being diverted through Ruswarp, and lengthy delays are expected.
The A171 has also been closed at the junction for Robin Hood's Bay with drivers travelling southbound being diverted through Robin Hood's Bay or Hawsker.
Officers arrived at the scene earlier this afternoon, but the road remains closed.
North Yorkshire Police has urged drivers to avoid the area and use alternative routes while emergency services respond.
The number of vehicles involved in the crash and whether there have been any casualties has not yet been reported.