The 48-year-old was detained on Monday in the northwestern city of Ponferrada in the province of Leon, and police are looking for a second Romanian suspect, the interior ministry said.
The detained man will appear in court on Wednesday, the ministry said in a statement.
Police launched their investigation after a group of over 100 people, purporting to celebrate a baptism, enjoyed a €2,000 ($2,100) banquet on February 27th at the Hotel Carmen restaurant in Bembibre, northern Spain, before promptly doing a runner.
A view of the outside of Hotel Carmen, where the baptism party took place. Photo: Google Maps
"They were dancing, then suddenly they had disappeared. In one minute, a hundred people had left," restaurant boss Antonio Rodriguez told Cadena Ser radio.
"They didn't leave in little groups -- no, they went all at once."
File photo of partygoers dancing the Conga. Stephen Dettling/Flickr
It later emerged that another restaurant about 10 kilometres (six miles) away in Ponferrada was also the scene of a similar heist in mid-February - that time by a group of around 200 people.
They were allegedly celebrating a wedding, when they also fled without paying a bill of some €10,000-12,000.
"In both crimes, the modus operandi was the same," the interior ministry statement said.
The arrested man posed as the godfather of the baptised child and the father of the groom when he made the bookings, local newspaper Diario de Leon reported.