Misha Collins is returning to Supernatural later this season in Episode 17. The actor appeared in the first two Season 7 episodes, Episode 7.01: Meet the New Boss and Episode 7.02: Hello, Cruel World as Castiel, but he hasn't starred in any episode since then. However, his guest-starring turn may be as a different character. Here's what executive producer Sera Gamble had to say about Misha Collins' return.
"It has always been our intention to bring back Misha in some form. We certainly can't say too much about where the story is going to go, but we love Misha and want to continue to work with him."
Misha Collins is also slated to guest star in two more episodes beyond Episode 17. Supernatural aired its fall finale, Episode 7.10: Death's Door this past Friday. The show is slated to return with new episodes on Friday, January 6 with Episode 7.11: Adventures in Babysitting.