West Mercia Police has put out an appeal for anyone who saw the crash, on the A49 in Felhampton yesterday.
The crash happened on the road between Craven Arms and Church Stretton just before 1pm, and involved a motorcycle travelling towards Shrewsbury, and a red Ford Focus travelling in the opposite direction.
Police said the motorcycle also struck another car, a red VW Polo.
A spokesman for the police said: "The rider of the motorcycle suffered significant injuries and was taken to hospital where they remain receiving critical care.
"The drivers of the other two cars received less serious injuries and were treated by paramedics at the scene.
"We would like to hear from anyone who witnessed the collision or may have dash cam footage that can help with the investigation by reporting it online at https://www.westmercia.police.uk/"