TORONTO — Canadian thesp Tatiana Maslany will topline in 10-episode sci-fi series “Orphan Black.”

Maslany stars in Toronto fest-preeming “Picture Day” and received a 2010 Sundance jury prize for her perf in “Grown Up Movie Star.”

In “Orphan” Maslany plays a street-wise orphan who witnesses the suicide of a woman whom she learns is her clone. Soon she and other clones realize an assassin is killing them off one by one. The series starts lensing in Toronto next month.

“Tatiana possesses all the intensity, charm and range that this complex role requires,” said Perry Simon, general manager of channels for BBC Worldwide America, which is distributing the series internationally.

“Orphan” is co-created by writer Graeme Manson (“Flashpoint”) and director John Fawcett (“Spartacus”), exec produced by Temple Street co-prexies Ivan Schneeberg and David Fortier (“Being Erica”) and produced by Temple in association with Bell Media and BBC America.