Season 6 (Arrow)

The sixth season of premiered on October 12, 2017, on The CW and concluded on May 17, 2018. The season consisted of 23 total episodes during its run.

Main Cast

 * Stephen Amell as Green Arrow (Oliver Queen)
 * David Ramsey as Spartan (John Diggle)
 * Willa Holland as Speedy (Thea Queen) *
 * Emily Bett Rickards as Overwatch (Felicity Smoak)
 * Echo Kellum as Mr. Terrific (Curtis Holt)
 * Rick Gonzalez as Wild Dog (Rene Ramirez)
 * Juliana Harkavy as Black Canary (Dinah Drake)
 * Katie Cassidy as Black Siren (Laurel Lance)
 * Paul Blackthorne as Quentin Lance

In-Universe Guest Stars

 * Grant Gustin as The Flash (Barry Allen)
 * Victor Garber as Firestorm (Martin Stein)
 * Caity Lotz as White Canary (Sara Lance)
 * Tom Cavanagh as Harry Wells & Reverse-Flash/Harrison Wells (Eobard Thawne)
 * Chyler Leigh as Alex Danvers
 * Dominic Purcell as Heat Wave (Mick Rory)
 * Candice Patton as Iris West
 * Franz Drameh as Firestorm (Jefferson Jackson)
 * Danielle Panabaker as Killer Frost (Caitlin Snow)
 * Melissa Benoist as Supergirl/Kara Danvers (Kara Zor-El) and Overgirl (Kara)

Notes:
 * 1) Willa Holland is credited as a series regular through 6x16.