The promising young defender penned a four-and-a-half year contract at the ESPRIT arena, with neither club making public the transfer fee involved.
Big move for Fortuna
The Düsseldorf outfit will no doubt be over the moon with Gül's arrival, capturing one of the most well thought of centre-backs in Germany.
The 18-year-old has been a regular in the national team's youth ranks, making 39 appearances across various age groups.
Gül also cemented his place at the heart of the Germany under-19 side last summer during the European Championships, despite being just 17 at the time.
Funkel has his say
Head coach Friedhelm Funkel was understandably pleased to bring in the centre-back, adding to his already exciting young group of players.
He could form a partnership with Robin Bormuth or Kaan Ayhan going forward, both players who have a similarly high potential.
Funkel explained, "We are very proud that we were able to sign Gökhan Gül. He is a very great talent and will take his next steps with us and develop further."
He concluded, "As an 18-year-old, we will introduce Gökhan to the under-23 side and the senior squad."
Bochum lose yet another talented youngster
The VfL faithful may have their Talentwerk programme to look upon but more than a few are becoming frustrated at the constant sale of young talents.
While there are financial constraints that play a part, Gül is the latest in a long line to depart for pastures new.
Fabian Holthaus, Gino Fechner, Lukas Klostermann, Leon Goretzka, Onur Bulut and Michael Esser are amongst those to have left within the last few seasons.
However, with the likes of Maxim Leitsch, Tom Baack, Vangelis Pavlidis and Görkem Saglam coming through there is still hope for the Ruhrpott club.