TV Line has made the exclusive official announcement that Tom Felton has been cast as a series regular in the third season of The Flash, as the character of Julian Dorn. Felton is best known for his villainous role of Draco Malfoy in the Harry Potter films.
The description of the character Felton will play reads as followed:
Felton is playing is Julian Dorn, a fellow CSI at the Central City Police Department who suspects there’s more to Barry Allen than just his good guy reputation.
Grant Gustin, star of The Flash was one of the first to welcome the actor into the series
Wait. I completely missed the @TomFelton announcement. I know what character he must be playing and I just got SO excited for this season.
— Grant Gustin (@grantgust) June 30, 2016
Source: TV Line