The airline paid the bill on Friday.
The French civil aviation authority said it had seized the plane at Bordeaux-Merignac airport as a "last resort" after France repeatedly tried to get Ryanair to pay back regional funds to the airline in 2008/09.
It was not immediately clear how much money French authorities were trying to reclaim from Ryanair.
"It is unfortunate that the state had to take such action, which led to the inevitable inconvenience of the 149 passengers on board the immobilised plane", the statement continued. The European Commission ruled in 2014 that aid was illegal and ordered the airline to reimburse the department.
Charente airport union leader Didier Villat told SudOuest newspaper: "To my knowledge it's the first time a Ryanair plane has been seized in this way".
The French civil aviation authority did not say how much money was involved, but regional airport officials said the sum was €525,000 (£457,000).
DGAC said 149 passengers were put on another flight on Thursday evening and arrived at their destination five hours late.
"Just because we manage a little airport in Charente it doesn't mean we are not going to defend ourselves", he added.
Ryanair did not publicly comment on the seizure.
Ryanair's fleet is made up mostly of Boeing 737-800 aircraft, which have a list price of more than $90 million each.
Ryanair is also fighting an order by Italian regulators to suspend a charge for carry-on bags.