The Owls head to the Toughsheet Community Stadium on Wednesday, August 13 (7.45pm) in the Carabao Cup opening round.
Sascha Lense, Chris Powell, Neil Thompson and Sal Bibbo have also departed Hillsborough ahead of the upcoming campaign.
There had been plenty of speculation over the German’s position at Wednesday amid the club’s problems off the pitch.
The Owls are under a three-window fee restriction imposed by the EFL over late payments to players, and are also under a transfer embargo, while owner Dejphon Chansiri is looking to sell the club.
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Rohl wrote on social media: “A very special time is coming to an end and I am incredibly grateful for the experiences we have shared over 21 unforgettable months together.
“I thank our chairman for his faith and giving me the opportunity to take my first steps as a manager.
“I thank my players for such a successful collaboration, your tireless commitment and for being great humans. I am proud of all of your personal resilience and efforts.
“This summer has been difficult and, in the end, the club and I came to the mutual decision to part ways. I understand the different thoughts and reactions to everything that has been going on during these past few months.
“I am extremely grateful to have had this opportunity. Even during the difficult moments and setbacks, I have always continued to feel the support from everyone. I take so many special moments away with me that will remain in my heart.”
Wednesday kick off their Championship campaign with a trip to Leicester City on Sunday, August 10.