Crunchyroll and Funimation both announced they will stream Attack on Titan Final Season later this year. No specific release date has been announced.
Funimation announced it will also simuldub the series.
MAPPA is in charge of the animation production for the final season, taking over from Wit Studio.
Crunchyroll describes the series as:
Known in Japan as Shingeki no Kyojin, many years ago, the last remnants of humanity were forced to retreat behind the towering walls of a fortified city to escape the massive, man-eating Titans that roamed the land outside their fortress. Only the heroic members of the Scouting Legion dared to stray beyond the safety of the walls – but even those brave warriors seldom returned alive. Those within the city clung to the illusion of a peaceful existence until the day that dream was shattered, and their slim chance at survival was reduced to one horrifying choice: kill – or be devoured!