With a towel covering his head, Forrest was escorted from a plane at Gatwick airport after flying in from the southwestern French city of Bordeaux and led into a waiting police van.
Police in the southern county of Sussex confirmed he had been charged with child abduction.
Forrest, 30, a married maths teacher, disappeared last month with a 15-year-old girl from his school in Eastbourne in Sussex on the southeast English coast.
The pair left Britain by ferry on September 20th, triggering a Europe-wide hunt that resulted in them being picked up by police in Bordeaux on September 28th.
The teenager, who is afforded anonymity under British law, was repatriated the following day while Forrest was detained in Bordeaux to allow a French magistrate to consider an international arrest warrant issued by the British authorities.
A French court ruled last week that Forrest should be returned to Britain.
Forrest did not contest the extradition at last week's hearing and, through his lawyer, has said he is keen for the "full story" of the elopement to be told.
"A 30-year-old man who was arrested for child abduction has been extradited from France and brought back to Sussex where he will be questioned by officers," a Sussex Police spokeswoman told AFP.