At 5.34am on Wednesday (March 3) police were called to a crash on Low Road, Hunslet.
The collision involved a cyclist and a white Peugeot Partner van, police said.
The male cyclist was taken to hospital for treatment to serious injuries that were confirmed as not being life threatening.
The driver stopped at the scene, police confirmed.
Low road junction of Church Street, Hunslet was closed this morning following the incident and police urged the public to avoid the area where possible.
A scene was put in place pending updates from the hospital.
The road closure was lifted shortly before 9am.
A West Yorkshire Police spokesman said: "Anyone who witnessed the collision or the circumstances leading up to it, particularly anyone with relevant dashcam footage, is asked to contact the Roads Policing Unit via 101 quoting log number 182 of March 3 or online via www.westyorkshire.police.uk/101livechat"