The Hotel Rwanda star is said to have already filmed her scenes as mysterious character Liz Ten for the cult U.K. sci-fi series, which sees a new Time Lord, Matt Smith, take over from David Tennant later this year (10).
A source tells Britain's The Sun newspaper, "Getting Sophie on board is a huge coup for the BBC. The forthcoming series has been criticised for being a bit light on the big names. But the feeling is less is more. Some fans thought the Kylie Minogue Christmas episode was a bit naff (poor)."
The casting news comes just a day after it was rumoured that Love Actually star Bill Nighy would be making a cameo appearance in an upcoming episode of the longrunning show.