Davies will be back in the title role, with Sheridan Smith reprising her part as fellow investigator Joey Ross. The 90-minute episode is titled 'The Clue of the Savant's Thumb'.
Speaking at the Royal Television Society Awards last night, Smith told Digital Spy: "It's lovely to be back together. It's always the same cast and crew and we've also got Rik Mayall and Joanna Lumley this time. It's like having an old family back together."
Davies and writer David Renwick recently confirmed that a full three-episode mini-series of the drama has been commissioned by the BBC and will begin filming in the autumn.
However, Smith isn't currently sure she'll be able to take part in the miniseries because of theatre commitments.
"I really want to be, but I'm going to be doing A Midsummer Night's Dream in the evenings. It depends if we can make it work. Fingers crossed," she said.
"With Alan's hair and the duffel coat - I love him. He doesn't need anyone else. He doesn't need a sidekick."
The last episode of Jonathan Creek was 2010 Easter special 'The Judas Tree'. A full series of the show hasn't aired since 2004.