Duff has signed a three-year contract and will join the Cottagers for an undisclosed fee.
“I am happy that my move to Fulham has been completed and look forward to joining in with the rest of the squad’s training programme immediately, in preparation for two important home matches this week,” Duff told the club’s official website.
“Fulham had a fantastic season last year and I know that having spoken to the manager in recent days that the club’s ambitions remain high and I am looking forward to the challenges ahead.”
