The officer suffered lower body injuries after being struck while standing outside a stationary police vehicle which was damaged in the incident.
The Met said a 21-year-old man was arrested at an address in the Archway area on Saturday.
He remains in custody.
Police were called just before 3pm on Thursday April 15 to reports of a vehicle in collision with a police officer at Dartmouth Park Hill near the junction with Tufnell Park Road.
The driver of the vehicle did not stop at the scene.
The injured officer was taken to hospital by London Ambulance Service (LAS) but his injuries were not life-threatening.
He has since been discharged from hospital, a Met spokesperson said.
Ken Marsh, chairman of the Met Police Federation representing rank-and-file officers, said: “My thoughts go out to this colleague as he recovers.
“Yet again an officer has been injured simply doing their job. This is what happens in London on a daily basis.”
Anyone who saw the incident, has dashcam or moving footage can call the police on 101 or tweet @MetCC quoting 4030/15APR.
Anyone who wants to stay anonymous can call Crimestoppers on 0800 555 111 or visitCrimestoppers-uk.org, the police said.