The 26-year-old has joined on a three-year deal with the option of an additional year.
Dejagah becomes Fulham's sixth signing of the transfer window after Dimitar Berbatov also agreed to join the West London club earlier on deadline day.
|17/2||West Ham are 17/2 with Bet365 to beat Fulham 2-1 on Saturday
The Iran international, made over 150 appearances for Wolfsburg and enjoyed an impressive campaign in the Bundesliga last term, scoring three times and notching ten assists.
However, the former Hertha Berlin man admitted that he is excited to be give the opportunity to test himself in the Premier League.
He told Fulham's official website: "I’m very happy to be signing for Fulham and to come and play in the Premier League.
"I know Sascha [Riether] well and he told me very good things about the Club and, after I had spoken to the Manager and heard about the project here, I was convinced. So I am happy to be here and will give my best for the Club and our fans."