The Upstairs Downstairs star will appear in the sci-fi drama's seventh series, according to Spotlight.
He will play a character named Kahler Jex in an episode helmed by Scottish director Saul Metzstein.
Scarborough has previously starred in Psychoville, Gavin & Stacey and Cranford, while his film credits include 2006's Notes on a Scandal and 2010's The King's Speech.
Sherlock's Rupert Graves, Harry Potter's David Bradley and The Fast Show's Mark Williams are among the confirmed guest stars for the next series of Doctor Who.
Williams will play a character named Brian Williams, Spotlight has also revealed.
Doctor Who's new executive producer Caroline Skinner recently promised that the latest series will "blow everybody's mind".
"We've got a lot of [the scripts] and the ones that are written are really, really epic and very exciting," she said.
Doctor Who will return to BBC One in the autumn.
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Watch Matt Smith discuss his future on Doctor Who below: