Billy Irving, from Argyll and Bute, is one of the so-called Chennai Six, who had been guards on a ship to combat piracy in the Indian Ocean, won an appeal against their convictions last week.
They were jailed in October 2013 after being charged with smuggling weapons and ammunition, but have now been given permission to leave India.
Mr Irving is expected to be the first of the six men to return home today.
The others – Nick Dunn, John Armstrong, Nicholas Simpson, Ray Tindall and Paul Towers – are expected to arrive in the UK tomorrow.
Foreign Secretary Boris Johnson said: “It is wonderful news that the men are returning to the UK.
“The Foreign Office has worked unstintingly on this case, lobbying on the men’s behalf, visiting them in prison, updating their families and maintaining close contact with their legal team.
“I pay tribute to those who have campaigned for the men, who will be delighted to see them return home after being separated for so long.”
The Britons were among 35 men detained while working as security guards. At the time, there was a significant risk from Somali pirates in the area, who would attack ships travelling through the Red Sea and around the Indian Ocean.
The men were accused of carrying unlicensed weapons, although they told Indian investigators that they had been granted permits by the UK’s Department for Business, Innovation and Skills.