The crash, on Bingley Road at around 5.30am, has been referred to the police watchdog.
In a statement, West Yorkshire Police said: "Police can now confirm that four males who were in a car which was involved in a road traffic collision at 5.30am on Bingley Road at the junction with Toller Lane in Bradford this morning have died.
"The road is currently closed and is likely to remain so throughout most of the day.
"Due to the nature of the incident it has been referred to the Independent Office for Police Conduct."
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