Police are appealing for witnesses to the collision, which happened in Harehills during the early hours of this morning.
A spokesman said: "A Ford Ka was travelling along Harehills Lane close to Sutherland Mount when it collided with a 24-year-old female pedestrian.
"She was taken to Leeds General Infirmary for treatment to serious injuries."
The driver, a 27-year-old woman, has been arrested on suspicion of drink driving.
Any witnesses are asked to contact police on 101 or use the live chat function available through the force website.