Suggestions by @aaronkime

Henry Simmons

as Steel in James Gunn's DC Cinematic Universe

Harry Holland

as Speedy/Red Arrow in James Gunn's DC Cinematic Universe

John Boyega

as Mr. Terrific in James Gunn's DC Cinematic Universe

Harrison Ford

as Highfather in James Gunn's DC Cinematic Universe

Derek Theler

as Orion in James Gunn's DC Cinematic Universe

Jannat Zubair Rahmani

as Starfire in James Gunn's DC Cinematic Universe

Lachlan Buchanan

as Booster Gold in James Gunn's DC Cinematic Universe

Katherine McNamara

as Vicki Vale in James Gunn's DC Cinematic Universe

Lance Lim

as Cosmic Boy in James Gunn's DC Cinematic Universe

Richard Madden

as Mirror Master in James Gunn's DC Cinematic Universe

Warwick Davis

as Mr. Mxyzptlk in James Gunn's DC Cinematic Universe

Haaz Sleiman

as Green Lantern (Simon Baz) in James Gunn's DC Cinematic Universe

Skai Jackson

as Bumblebee in James Gunn's DC Cinematic Universe

John Krasinski

as Blue Beetle in James Gunn's DC Cinematic Universe

Forrest Wheeler

as Damian Wayne in James Gunn's DC Cinematic Universe

Corey Hawkins

as Red Tornado in James Gunn's DC Cinematic Universe

Numan Acar

as Vandal Savage in James Gunn's DC Cinematic Universe

Emanuela Postacchini

as Zatanna in James Gunn's DC Cinematic Universe

Luke Mitchell

as John Constantine in James Gunn's DC Cinematic Universe

Zachary Levi

as Shazam in James Gunn's DC Cinematic Universe