The 21-year-old featured just twice for Arsenal's first team, having arrived at the club from Borussia Dortmund as a youth prospect.
An attacking midfielder with an eye for goal, Eisfeld scored three times on Arsenal's close-season tours of Asia in 2012 and 2013 but failed to secure a regular spot at the Emirates Stadium.
He will link up with compatriot Felix Magath for Fulham's first season back in the second tier - having signed a two-year contract that includes the option of a further 12 months.
Magath and Fulham have been busy in the transfer market since their drop from the top flight last season - bringing in strikers Ross McCormack and Adam Taggart after a number of players moved on from Craven Cottage.
Konstantinos Stafylidis was another recent arrival - the Greek joining on loan from German side Bayer Leverkusen - and Fulham announced a further signing on Wednesday, with former Cologne winger Adil Chihi arriving on a free transfer.
Chihi, 26, has penned a one-year deal with the option of an additional 12 months.