West Yorkshire Police officers were called at 8.03pm to a collision involving a pedestrian and a green First West Yorkshire bus.
Call Lane was closed between 8pm and 11.40pm while police and ambulance crews worked at the scene.
A man was taken to hospital with serious, potentially life-threatening injuries.
Four police cars, an ambulance and a trauma team were called to the scene, which was reported as Boar Lane on social media, but police confirmed as Call Lane.
A bus was put behind police tape while officers carried out investigations.
There is no indication yet about the man's age.
The road is open as normal on Saturday.
Photos: Benjamin Wilson/Leeds Crime & Incidents group