Officers say that the crash happened on the A272 at around 11.30am yesterday (Monday) and involved a silver Ford Fiesta, a white Ford Fiesta and a Skania tipper truck.
“Two other women, both aged 23 and from Kent, were taken to hospital with serious injuries.”
Road closures remained in place while police, fire and ambulance crews, and air ambulance service, responded to the incident.
Detective Sergeant Rob Baldwin, of the Surrey and Sussex Serious Collision Investigation Unit, said: “We would particularly like to speak with anyone travelling on the A272 between Cowfold village and Littleworth Lane to the west, on Monday morning between 11.15am and 11.30am, who has dash camera footage.
“We’d also like to speak with any resident or business who has CCTV footage showing the road between those locations.”
Information can be reported by email to [email protected] or by calling 101 and quoting Operation Banwell.