It was announced during the 5th Anniversary Event "/Beginning Next" and on the official website for the IDOLiSH7 franchise that the anime's third season will have two cours. The first cour will premiere sometime this year.
They also announced that the staff from the previous seasons will be returning for Season 3.
Makoto Bessho is once again directing the new season at TROYCA, and Ayumi Sekine is again in charge of the series scripts. Ei Aoki is returning to supervise, and Kasumi Fukagawa is again adapting the original character designs by Arina Tanemura. Masami Inomata is back as the chief animation director.
Crunchyroll describes the series as:
A group of aspiring idols gather at Takanashi Productions and are entrusted with the company's future. The seven men who have just met represent a variety of totally different personalities. However, they each have their own charm and possess unknown potential as idols. Forming a group, they take their first step together as "IDOLiSH7." Their brilliantly shining dancing forms onstage eventually begin captivating the hearts of the people. In the glorious but sometimes harsh world of idols, they aim for the top with dreams in their hearts!
A group of aspiring idols gather at Takanashi Productions and are entrusted with the company's future. The seven men who have just met represent a variety of totally different personalities. However, they each have their own charm and possess unknown potential as idols. Forming a group, they take their first step together as "IDOLiSH7." Their brilliantly shining dancing forms onstage eventually begin captivating the hearts of the people. In the glorious but sometimes harsh world of idols, they aim for the top with dreams in their hearts!