The 21-year-old, who was the AFC's Youth Player of the Year in 2013, made the move to the Serie A side from Caykur Rizespor who plays in Turkey's Super Lig.
"I know all about Serie A. I chose Udinese because I feel they are a big club,” Adnan told reporters at Friday’s press conference.
"I'm proud to be the first Iraqi footballer to play in Italy and I am prepared to play in any position. I want to be a success with Udinese.
"I believe I can handle myself against any forward in the world.
"I also want to thank all my Iraqi fans. They've given me immense support.”
The left-back, fondly referred to as the ‘Iraqi Gareth Bale’, started his professional career with hometown side Baghdad FC before transferring to Caykur three years later where he scored three goals in 41 appearances.
He also has 25 caps for the national U-20 and U-23 teams and represented the senior national side 34 times, appearances which included January’s AFC Asian Cup 2015 in Australia.