Katie Cassidy, Willa Holland Join Green Arrow Pilot

Swifter than an arrow, The CW is speeding through the casting process on its upcoming Green Arrow pilot. Two new actors have joined the fray now, bringing the current cast list up to five names.

TV Line reports that "Melrose Place" alum Katie Cassidy has scored the role of Dinah "Laurel" Lance — the woman who goes on to become Black Canary — in the pilot. Additionally, Deadline adds that "The O.C." veteran Willa Holland has joined the show as Oliver Queen's younger sister Thea.

Details about both characters beyond the jump.

Original character breakdowns described Dinah as follows:

"28 years old, smart sexy, Laurel is a legal aid attorney determined to use her life as a one-woman war against the 1% following the death of her younger sister Sara. A sister, who as luck would have it, just so happened to have died aboard Oliver’s yacht."

As for Thea:

"Oliver’s Lolita-esque sister, Thea was a 12 year old girl when he went on his infamous yachting voyage — but now she’s a celebutante who’s testing the boundaries of acceptable behavior. Thea loved her big brother with all her heart, and is delighted to have him back in her life — but she’s spreading her wings, and is unprepared for Oliver to become the Bad Cop in the family, restricting her access to boys and drugs."

Stephen Amell, David Ramsey and Susanna Thompson round out the "Arrow" cast.

Tell us what you think of the new additions in the comments section and on Twitter!