According to Deadline actor Nathan Darrow (House Of Cards) has been cast as the recurring character of Victor Fries aka Mr. Freeze on Gotham.
Deadline has this description for the character, which we aren’t sure is for Gotham or them simply recapping his story from the comics:
Victor begins as one of Gotham’s preeminent cryogenics engineers. Though ferociously smart and eminently capable in his work, Victor struggles to make meaningful connections with others. The one exception is his wife, Nora, who has tragically fallen ill with a terminal disease. Victor’s love for Nora knows no bounds, and as her condition worsens, he goes to extreme measures to figure out a way to freeze her before she dies. This harrowing journey leads to his transformation into the legendary DC villain Mr. Freeze.