The 23-year-old Serbian was part of the Wolfsburg team that finished as Bundesliga runners-up in 2009, and arrives at the Commerzbank Arena on a three-year contract for an undisclosed fee.
"I am now happy to be in Frankfurt," Medojevic said on Monday. "It was a little stressful for me in the last few weeks, because I did not know if I would be staying in Wolfsburg or not.
"When I heard that Eintracht Frankfurt were interested in me, I immediately said that I would like to go.
"The team has a huge potential. I am very happy to be here, in a great club with great tradition.
"I've played here a few times away and the support of the fans is amazing. I'm really happy to play here now and want the team to succeed."
Medojevic made 28 league appearances during his two-and-a-half years with Wolfsburg.