Goalkeeper Steven Benda said "it was a very easy decision" to sign for Fulham from Swansea.
The 24-year-old has signed a contract until the summer of 2026, with the option for the club to extend by a further year.
Benda came through the youth ranks in Germany with 1860 Munich, before joining Swansea in August 2017.
He made 31 appearances for the Swans, keeping eight clean sheets.
Benda said: "I’m really happy. It’s a massive club with a lot of history and tradition, so I’m really happy to be here.
"Just look at this stadium, and the Club itself, playing for Marco Silva, it was a very easy decision."
Tony Khan added: "I'm pleased to welcome Steven Benda to Fulham.
"He's a talented young goalkeeper, and while he's currently recovering from injury, we've monitored him for some time and believe that he'll be a valuable addition to Marco’s squad upon his return."