Officers in a marked police vehicle were alerted to a grey Audi driving without its lights on in Dunstable shortly before 10.30pm on Saturday, Bedfordshire Police said.
The 41-year-old male driver failed to stop for police, sparking a police pursuit as the Audi drove off on the A5183 towards Markyate.
At around 10.37pm, the Audi left the road and collided with a tree near Caddington, police said.
No other vehicles were involved in the crash.
Officers carried out first aid and were later supported by emergency services, but the driver was pronounced dead shortly before 11.30pm.
Police said his next of kin have been informed and are being supported.
Bedfordshire Police has referred itself to the Independent Office for Police Conduct, in line with mandatory requirements.
The office has since launched an investigation.
