We already know that the first season of Loki, currently due sometime in 2021, is going to be six episodes much like the other Marvel Studios limited series on Disney+. There has been some speculation that Loki could be a multi-season show, but nothing completely official yet. Until now.
Variety has an interview with Clark Gregg about the final season of Agents of S.H.I.E.L.D., which starts this Wednesday on ABC, and he had this to say about Loki from what Tom Hiddleston told him:
But I’d be lying if I didn’t say boy, that would really be interesting to start the experiment over, doing 10 episodes or 12 episodes the way Tom Hiddleston told me he was doing [on “Loki”] with that kind of budget and that Marvel Cinematic production team.
So if the first season has already been confirmed to be six episodes, then there are four to six additional episodes that they’re going to be making. That would make up a second season right there.