Little Witch Academia is a series that has an interesting history. Originally a debuting as a 30-minute short in 2013, it received a sequel hour-long movie in 2015. After both projects received a positive reception, a fully-fledged anime season (which was split into two in international releases) was later greenlit and debuted in 2017. All three follow the exploits of Akko and her friends, Lotte and Sucy, as they attend a school that trains them in the ways of magic. As a Studio Trigger production, the series stood out among its peers as a family-friendly adventure, something that deviated from the production studio's usual MO.
Despite this, the series was still beloved by fans of Trigger and newcomers alike, establishing it as one of the more popular titles from the studio. But its beloved status has still not led to a follow-up season coming to fruition, even though Trigger is open to the idea and has tried to get it up and running in the past. Director Yoh Yoshinari has expressed that there was a desire for another season to be made, but it simply never got off the ground. This, in part, can be attributed to the sudden passing away of Michiru Shimada, the screenwriter of both the 2015 movie and 2017 series. As one of the creative leads on the project, it's unsurprising that the series would struggle to find a direction to take the new season.
Instead, the studio chose to move on to its next project, BNA: Brand New Animal. Alongside this, Trigger has already announced its next title Cyberpunk: Edgerunners, which is tied into the highly-anticipated video game, Cyberpunk 2077, and not set to premiere until 2022. This means that Little Witch Academia will either not be receiving a sequel, or it is planned to be announced much farther in the future. The former is more likely than the latter.
This is par for the course for Trigger, as even its most popular properties rarely receive sequels. Kill la Kill, one of the studio's biggest titles, did receive a pair of specials on its Blu-ray and DVD releases -- two 19-minute shorts. The only true sequel for a series will be Inferno Cop's second season, which was announced at AnimeNEXT in 2017. However, it has yet to be released and still hasn't had any further mention besides a small nod through a BNA Easter egg.
All signs seem to point toward a new season of Little Witch Academia being released rather unlikely. Although, given the title's unique history and popularity, fans can always hold out hope for a continuation of Akko and her adventures.