The incident between two cars happened on Uxbridge Road at around 4.45am this morning (January 2).
Officers arrived with paramedics who took a woman in her 20s to hospital.
One officer was closing the road when they were hit by a third vehicle. They were taken to hospital by their colleagues.
The conditions of the officer and the woman involved in the initial crash are not life-threatening or changing.
A spokesperson for the Met said: “Officers attended Uxbridge Road, Ealing at around 4.43am on Friday, January 2, following a collision involving two cars.
“A woman in her 20s was taken to hospital by the London Ambulance Service, where her injuries have been deemed not life-threatening or life-changing.
“While setting up a cordon at the scene, an officer was subsequently involved in a collision with a third vehicle.
“They were taken to hospital by police colleagues, where their injuries were deemed not life-threatening or life-changing.
“No arrests have been made in relation to either collision and enquiries continue.
“Anyone who has information or dashcam footage that could help police should contact 101 quoting CAD 890/2Jan.”
