The actor, who is starring alongside Patrick Stewart in a Royal Shakespeare Company production of Hamlet, said he loves everything about the BBC series.
"I'm excited to be doing Hamlet," he told Doctor Who Magazine, "but I have got very at home in Cardiff. I love that crew. I love that set-up. I love the show, so I'm missing that. I miss Russell's writing."
"It's nice to know that I'm coming back," he continued, referring to the four specials due to be filmed in 2009. "I'll be reminded of [Doctor Who] in some shape or form pretty much every day until I start filming again in January."
Tennant also joked that "Shakespeare's all right, but he's lacking in spaceships".
> Click here for our review of Doctor Who's fourth season