The officers were suspended after shooting Jean Charles de Menezes on July 22 last year, but the police lifted the restrictions on them after prosecutors declared that there was not enough evidence to charge them with any crime.
"Both officers will now resume full operational duties," London's Metropolitan Police said in a statement.
Mr Menezes was shot seven times in the head at Stockwell Underground train station in south London a day after an alleged failed attempt to replicate the suicide attacks on the city’s public transport system on July 7, 2005, in which 56 people died, including four bombers.
The two firearms officers were among several police officers against whom the Crown Prosecution Service (CPS) considered criminal charges over Mr Menezes’ death.
But the CPS ruled on July 17 that there was "insufficient evidence" to charge anyone after concluding that the two who fired the fatal shots had acted in good faith.
The police officers "genuinely believed" the Brazilian "had been identified to them as a suicide bomber," the CPS said.
British police were on high alert after the attacks on London’s transport system two weeks earlier.
On the other hand, the CPS said it had evidence to prosecute the office of the Metropolitan Police Commissioner under the Health and Safety at Work Act 1974 for failing to provide for the health, safety and welfare of Mr Menezes.
The force still has to decide whether either of the officers should face disciplinary proceedings.
Its decision will have to be ratified by the police watchdog, the Independent Police Complaints Commission (IPCC). If it disagrees, it can order the force to hold a misconduct hearing.
"This matter will now be reviewed to establish whether there have been any misconduct issues," the police said.
"While disciplinary matters are under review we are pleased with the CPS decision and are pleased for the officers and their families who have faced much uncertainty over the last year."
The force said that there were other officers who remained on restricted duties as a result of the killing, but refused to say how many.
Family outraged
The family of Mr Menezes, which had been furious at the CPS decision, was again outraged that the police force decided to put the firearms officers back on full duty.
The dead man's family was "very, very upset" and "in pieces," according to Asad Rehman, spokesman for the Justice4Jean campaign.
"Every day it seems that the Metropolitan Police just rubs more salt in the wounds," Mr Rehman said. "They could not have been more hurtful."
The circumstances surrounding the incident still remain a hotly disputed issue. London police chief Ian Blair has been heavily criticised and is still facing calls for his resignation over the blunder.