The 32-year-old was detained on a European arrest warrant around 9.30pm last night after stepping off an EasyJet flight from Belfast
Civil Guard officers had been tipped off and were waiting for him at the Costa Blanca airport.
He is now due to appear at an extradition hearing in Madrid where he will be asked if he consents to extradition or not.
He is understood to have been arrested in connection with the murders of Dublin gangland figures Anthony Burnett, 32, and Joseph Redmond, 25.
The pair, from Ballybough, were found in the front seat of a burning car close to Ravensdale Forest, Co Louth, in March 2012.
It is believed the men were tortured and shot in the head before the vehicle was set alight.
A 41-year-old from Rathmines, south Dublin city, was arrested over the crime in April 2014.
A spokesman for the Civil Guard in Alicante said today: “I can confirm we have arrested a 32-year-man on foot of an extradition warrant in connection with a double murder.
“He was held as he arrived at Alicante Airport on a flight from Belfast.”