The short, brutal answer is never. But the more interesting, more nuanced answer is that Mr. Inbetween already gave us its Season 4—we just didn't recognize it because it didn't arrive with a marketing blitz or a "previously on" recap. The show’s final three-episode run (officially Season 3, released in 2021) functions so perfectly as a terminal chapter that the very concept of a fourth season would represent not a continuation, but an undoing.
Never. And thank god for that.
In an era of bloated "prestige TV" where shows are stretched into zombie-like half-lives by corporate mandates, Mr. Inbetween stands as a radical act of artistic discipline. It lasted 26 episodes. That is it. That is the whole story. It arrived, it devastated, and it left before it could become a parody of itself. mr inbetween season 4 release date