Frederick IV (French: Ferry) (15 April 1282 – 23 August 1328[1]), called the Fighter, was the Duke of Lorraine from 1312 to his death.

Frederick was born in Gondreville, the son and successor of Theobald II and Isabella of Rumigny.

[2] On 18 October 1314, at the Diet of Frankfurt, the prince-electors of the Holy Roman Empire failed to elect as successor to Henry VII, Holy Roman Emperor, either the Habsburg claimant, Frederick the Handsome, the duke of Austria, or the Wittelsbach, Louis IV of Bavaria.

In 1324, he participated in an expedition in Aquitaine against Edward II of England's estates, for Charles IV had built a fortress illegally on Edward's territory and had sent his uncle, Count Charles III of Valois, against the English possessions after Hugh le Despenser and the Younger Despenser imprisoned Isabella of France, Charles IV's sister and Edward's queen.

He joined Philip VI of France, on his succession in 1328, and fought and died at the Battle of Cassel.