Roy Eccles, 55, and his wife Judith, 49, were stabbed to death in Kaminarata on the island of Cephalonia in the early hours of Thursday at their villa.
Labros Pappas, 22, who lived in the same village as the couple, and Edward Elmazi, 19, were arrested at gunpoint on the neighbouring island of Lefkas after a brief chase.
The arrests came after a tip-off from a member of the Albanian immigrant community on Cephalonia.
A police spokesman said the pair had confessed to ransacking the couple's villa and killing them. They left cameras, gold jewellery and other valuables behind them when they fled.
Detectives took samples from blood stains found on the men's clothing.
It had emerged the two farm workers were missing from Cephalonia after police questioned and fingerprinted more than 100 Albanians in the wake of the killings.
Impoverished Albanians flooding into Greece have been accused of a number of crimes recently.
Mr and Mrs Eccles retired to Cephalonia from their home in St Neot's, Cambridgeshire, last October. Their bodies were discovered by a neighbour, Richard Coward, 52, and Mrs Eccles' brother, Derek Wooding.
Mr Coward said: "We still do not understand why they were murdered. I am angry. There is no rhyme or reason to it - no logic."