Rodallega joins the Cottagers after his three-and-a-half-year spell at Wigan Athletic ended upon the expiration of his contract this summer.
During his time at Wigan, Rodallega scored 24 goals in 112 Premier League appearances. The most memorable of those came in the final match of the 2010-11 campaign, when his header sealed a 1-0 win at Stoke City which preserved the Latics' top-flight status for another season.
The 26-year-old has signed a three-year deal with Fulham, joining Croatian Mladen Petric as another new forward at manager Martin Jol's disposal.
"I’m thrilled to have signed for Fulham Football Club," Rodallega told the club's official website. "I wanted to stay in England and I’m delighted that I now have this opportunity with Fulham.
"I would like to thank the staff and fans of Wigan Athletic for three and a half wonderful seasons there.
"I’m looking forward to pre-season training with the rest of the Fulham squad and starting a new chapter in my career."
Jol added: "There has been a lot of interest in him from other top flight teams in England and abroad, so to be able to add his quality to our squad is a massive boost this early in our preparations for the new campaign.
"He is a great addition and I think he will contribute very well to our style and philosophy here."
Fulham released strikers Pavel Pogrebnyak and Andy Johnson this summer, having sold Bobby Zamora to rivals Queens Park Rangers in January.