The motorcyclist, a man from Wakefield, was taken to Leeds General Infirmary by air ambulance after the accident yesterday afternoon.
It happened on Coldhill Lane on the outskirts of Sherburn-in-Elmet at around 1.45pm and involved a beige, Skoda Octavia travelling from the direction of Lotherton Hall towards Sherburn, and a blue and white, BMW motorcycle travelling in the same direction.
The road remained closed until 7.30pm to allow emergency services to attend to the casualty and for police investigators to examine the scene.
The driver of the Skoda, a man aged 26 from Leeds, was uninjured.
He was arrested on suspicion of causing serious injury through dangerous driving and has been released while under investigation.
Officers are appealing for any witnesses who have not already spoken to them, including anyone who saw either vehicle travelling between Lotherton Hall and Sherburn, to contact them.
Anyone with information can call North Yorkshire Police on 101, select option 2 and ask for Traffic Constable Mark Mullins of the Major Collision Investigation Team at Tadcaster, or via email [email protected] quoting reference 12180195051.