Hussain Osman was flown from Rome on a private charter jet which landed at RAF Northolt in west London at 1.39pm. Detectives from Scotland Yard's extradition unit were on board the plane with him.
After it landed, Osman was formally arrested under British law on suspicion of conspiracy to commit murder, attempted murder and alleged explosives offences.
A convoy of vehicles, including police outriders, was waiting to take him to the high security Paddington Green police station and there was also extra security around the airport perimeter.
The 27-year-old Ethiopian-born terror suspect, also known as Hamdi Isaac, will be formally charged at the police station.
He will appear at Bow Street Magistrates' Court, sitting at the high security Belmarsh complex in south east London, tomorrow morning.
The process of bringing Osman back to the UK began early this morning.
At just before 9am, he was taken from his cell at Rebibbia jail on the outskirts of Rome and driven in a prison van to Ciampino airport.
On arrival the convoy drove up to the front of the waiting plane and Osman, who had a blanket over his head, was brought out by police officers.
Amid tight security, he boarded the plane at just after 11am British time.
The details of the operation to bring him back were kept a closely guarded secret by Italian and British police, and even Osman was not told which day he would be returning to the UK.
Osman, who is accused of trying to blow himself up on a train at Shepherd's Bush, west London, has been held in Rome since his arrest there a week after the attempted bombings.
He has already been questioned at length by British and Italian anti-terror police in the Italian capital.
Judges there had agreed to an extradition request by British authorities but the process of returning him to Britain was delayed when Osman's Italian lawyer Antonietta Sonnessa appealed.
The appeal was lost on September 13, after which the Italian authorities had 10 days to arrange his return.
The short length of the extradition process, two months, has been hailed as a success for the new system of European arrest warrants for terror suspects.
During his interviews with police in Italy, Osman claimed his rucksack "bomb" was packed with flour and was meant to scare people but not harm them.
Three other alleged would-be suicide bombers have been charged in the UK over the failed bombings.
They are Ibrahim Muktar Said, 27, of Stoke Newington, north London, Ramzi Mohamed, 23, of North Kensington, west London, and Yassin Omar, 24, of New Southgate, north London.
All three are charged with conspiracy to murder and making or possessing an explosive with intent to endanger life or cause serious injury on July 21.
Manfo Kwaku Asiedu, 32, of Finsbury Park, north London, was also charged with conspiracy to murder and conspiracy to cause explosions likely to endanger life.
They have been remanded in custody until their next court appearance before a judge at the Old Bailey on November 14.Reuse content