Today saw Warner Bros. announce details for their slate of Justice League movies, which made mention that Ezra Miller will star as The Flash in the speedster's standalone movie which is due out in 2018.
We can also speculate that Ezra Miller will be featured in the "Justice League Part One" movie that is due out in 2017, as well as possibly a cameo in Batman Vs. Superman, which is rumored to feature the Justice League appearing at the end of the film.
Ezra Miller, a 22 year-old actor from Wyckoff, New Jersey of Ashkenazi Jewish and German descent, is known for roles in The Perks of Being a Wallflower, We Need to Talk About Kevin, Royal Pains, Californication, recently filmed Trainwreck, and is currently filming The Stanford Prison Experiment.
As a side note, Grant Gustin also plays The Flash on the CW TV series, which is set a part from the WB movie universe.
Video of Ezra Miller: