'The Flash': Grant Gustin Cast As Barry Allen For 'Arrow' And Potential Spin-Off

"Glee's" Grant Gustin has been cast as Barry Allen (AKA The Flash) on "Arrow," The CW announced Friday. He'll appear in episodes 208, 209 and 220 of "Arrow" Season 2, and if the character is well-received, headline the proposed Flash spinoff.

Barry Allen is a Central City assistant police forensic investigator who arrives in Starling City to look into a series of unexplained robberies that may have a connection to a tragedy in his past. A comic book fan boy, Barry is obsessed with the Arrow, unaware that working with Oliver (Stephen Amell) and Felicity (Emily Bett Rickards) to solve the crime has brought him right into the dangerous world of the vigilante.

Gustin is best known for his role as Sebastian Smythe, the scheming, openly gay member of the Dalton Warblers who set his sights on Blaine (Darren Criss) on "Glee."

Other new additions for "Arrow" Season 2 include Summer Glau as Isabel Rochev; "Spartacus" star Cynthia Addai-Robinson as DC Comics villain Amanda Waller; "Orphan Black's" Dylan Bruce as a new coworker of Laurel's (Katie Cassidy); Caity Lotz as Sara Lance, who will play an iteration of Black Canary; Michael Jai White as the Bronze Tiger; Kevin Alejandro as Sebastian Blood; and John Barrowman and Kelly Hu who will return as Malcolm Merlyn and China White respectively.

"Arrow" Season 2 premieres Wednesday, October 9th at 8 p.m. ET on The CW.

"Glee" and "Arrow" fans, what do you think of Gustin's casting?