Fugitive Andrew Moran was captured in a dramatic raid at a luxury villa in the Costa Blanca, police said.
An elite team of armed officers swooped on the robber while he was relaxing by a swimming pool.
They recovered two handguns, 60 rounds of ammunition and a machete at the property.
Moran was on the most wanted list for Crimestoppers' Operation Captura campaign.
One of Britain's most wanted fugitives has been arrested in Spain, police said.
Andrew Moran, 31, from Salford, Greater Manchester, was arrested in the resort of Calpe in Alicante on Friday, the Serious Organised Crime Agency said.
Moran, who has been on the run for over four years, fled the country in 2009 after he vaulted the dock in a Burnley courtroom as he went on trial over a £25,000 armed robbery of Royal Mail guards.
He was convicted in his absence for the theft in 2005 in Colne, Lancashire.