The 14-year-old boy, 22-year-old man, 23-year-old man, and two 24-year-old women were in a black Mercedes A200 which hit parked cars and a tree on the A58 Halifax Road, near Glenfield Garage petrol station, at around 6pm.
All were taken to hospital and the three most seriously injured - the 23-year-old man, a 24-year-old woman and the teenager - are continuing to receive treatment in Leeds General Infirmary.
Police are appealing for anyone with information about the accident to get in touch,
The Mercedes was heading towards Sowerby Bridge when the crash happened.
The road was shut for several hours yesterday while emergency services dealt with the incident.
Anyone with information that might help with the police's investigation, particularly anyone with relevant dashcam footage, is asked to contact the Roads Policing Unit via on 101 quoting reference 13210359439 or online via www.westyorkshire.police.uk/101livechat.