The collision, which involved a black KTM motorcycle and a blue Mini Cooper, happened shortly before 1pm on Sunday on Cookridge Lane, at its junction with Mavis Lane.
The motorcyclist, a 41-year-old man, sustained serious pelvic and abdominal injuries.
Two ambulances and a rapid response vehicle were sent to the scene and paramedics took the casualty to the major trauma centre at Leeds General Infirmary.
Police are keen to speak to anyone who has witnessed the collision itself or who saw either of the vehicles involved immediately beforehand.
Information can be passed to the Eastern Area Safer Roads and Neighbourhood Support Team via 101, quoting log 1049 of 15/07.