The incident took place on Wednesday September 15 at about 7.10pm just south of the junction of the A361 and Chipping Norton Road.
A green Ford Fiesta and a blue Ford KA were involved in a collision.
The passenger in the Fiesta, a 24-year-old man, suffered serious injuries and was taken to hospital for treatment where he remains in a serious condition. The driver of the Fiesta, another 24-year-old man, also suffered injuries and was taken to hospital where he is in a stable condition.
Man seriously injured in crash near Banbury - Police make witness appeal. Warwickshire man arrested
Motorcyclist fights off three robbers in Chipping Norton
Crowds get acclimatised as Cropredy festival heats up and the music is scorching
Man jailed for sexually abusing a girl in Oxfordshire
Man jailed after leading police on a 100mph chase in Bicester
The driver of the KA, a 58-year-old woman, suffered serious injuries and was also taken to hospital where she remains in a stable condition. A 15-year-old girl who was the passenger in the KA suffered minor injuries and did not require hospital treatment.
No arrests have been made.
Investigating officer, PC Andy Wickens of the Roads Policing Unit, said: “I would like to speak to anyone who saw this collision, or who has any dash-cam footage which could be relevant to our investigation.
Multiple emergency services responded to the collision, including the Oxfordshire Fire and Rescue Service, the South Central Ambulance Service NHS Foundation Trust, and Thames Valley Air Ambulance.
A spokesperson for South Central Ambulance Service said: "We sent to the scene an ambulance officer, two ambulance crews, the critical care car and two air ambulance crews.
"They were assessing and treating three patients who were taken to hospital.
"One patient was assessed and treated at the scene and flown to University Hospital Southampton. Two patients following treatment at the scene for their injuries were taken to John Radcliffe Hospital."
The Banbury Guardian reported on the collision earlier today (Friday September 17) here: https://www.banburyguardian.co.uk/news/people/fire-crews-rescue-three-people-medically-trapped-after-two-vehicle-collision-on-a361-near-chipping-norton-3386564