The European General Court made the order because the French politician had not proved his assistant was performing duties in Mr Le Pen’s role as an MEP.
Fellow Front National MEP Bruno Gollnisch has also been told to return £246,000.
It comes after a number of members of the far-right group faced accusations of using European Parliament money to pay party staff.
Leader Marine Le Pen has also been asked to hand back £300,000 in funds.
The rulings are another blow to the reputation of the party, which this week will unveil a plan to change its name in an attempt to woo back voters.
A Lille congress on March 10 and 11 is being used by Ms Le Pen as a chance to reassert her leadership following a bruising election campaign that saw her lose to Emmanuel Macron.
The 49-year-old said: “In France, there is a habit of announcing our death as soon as we’re somewhat weakened.
“But each time they buried us, we came back stronger.
“The name change will mark the end of a chapter and the start of a new one, that of a party suited to being in power and striking alliances.”
Alongside the name change, the party plans to refocus on immigration but will water down its opposition to the single currency.
Party member Sebastien Chenu said: We’re keeping our fundamentals, our basis – security, immigration.
“But new faces will appear, and we have changed our line on Europe, on the euro.”
Ms Le Pen seeks to head a more inclusive “patriotic” camp as small and large parties alike scramble to reinvent themselves after the unprecedented election victory of Mr Macron’s centralist programme.
But she faces an uphill struggle, with a poll this week showing nearly three-quarters of French people think she will be a bad president.