The Serbian striker spent the last six months of last season on loan at the west London club, helping them achieve promotion from the Championship.
He will take the no.9 shirt at Craven Cottage, and signs a five-year deal at the club.
"We are delighted to confirm Aleksandar Mitrović’s return on a permanent deal for an undisclosed fee from Newcastle United," Fulham said in a statement.
"The popular striker has signed a five-year deal, keeping him at Craven Cottage until at least the summer of 2023, and will wear the number nine shirt.
"Mitrović originally joined the Whites on loan at the 11th hour on deadline day in January, and went on to have a hugely significant impact in our promotion to the Premier League.
"The 23-year-old striker proved to be the perfect fit for Fulham, scoring 12 times in just 17 starts to help the team reach Wembley."
The player himself is delighted to be back with Fulham, after falling out of favour with Rafa Benitez at St James' Park.
“I’m very glad and happy and proud to finally be here and officially become a Fulham player. I’m happy to the moon and back," he told fulhamfctv.
“I have love for the fans. They’re amazing fans and I have a really good connection with them."
30 July 2018