The photo and snippet of video show Malkovich as a serious-looking Poirot, wearing a hat and sporting a short, white beard and mustache.
"I'm honored to have been asked to play Hercule Poirot. It's a role that's been played by a number of excellent actors, and I am enjoying the numerous challenges this part presents. I have great respect for Sarah Phelps' screenplay and hope to do both she and Agatha Christie's creation some measure of justice," Malovich said in an accompanying news release.
The British broadcaster has also announced who else will appear in the three-part, 1930s murder mystery. Joining the previously announced Rupert Grint, Tara Fitzgerald and Andrew Buchan will be Shirley Henderson, Kevin McNally, Gregor Fisher and Jack Farthing.
Alex Gabassi is directing the miniseries.