The leader of the Prolethean cult in Season 2 is Ari Tasarov.
I Knew It: Helena's survival was predicted by a large enough portion of the fanbase that there was a Fan Nickname for it: "The Ballpit of Denial". Ok, fair enough. What pushes this into truly eerie territory is the explanation for her survival: she is a mirror twin, and her heart was on the reverse side of her body as everyone else's. This exact explanation was predicted by fans from the mere fact that she is left-handed.
Plays Great Ethnics: Tatiana "Tania" Maslany, is Romanian-Canadian. A sort of female counterpart to Tony Shalhoub.
Promoted Fanboy: Patrick Adams (of Suits fame) has stated that he loves Orphan Black and of Helena in particular. He has a guest spot in "To Hound Nature in Her Wanderings" in which he gets to romance Helena very, very briefly.
Real-Life Relative: Alison's adopted children, Oscar and Gemma, are played by siblings Drew and Millie Davis.
There are a lot of Ginger Snaps connections. For one, Alison lives in Bailey Downs, where the first movie takes place. And just like Ginger, Olivier has a tail (albeit a prosthetic one), and gets it cut off (just as Ginger tried to do to hers). Tatiana Maslany and Eric Johnson (Chad) were also in the sequel, Ginger Snaps 2: Unleashed, as Ghost and Tyler. This is not surprising, given that John Fawcett, who directed the first movie (and produced the subsequent movies), is one of the creators of Orphan Black.
A character in a conspiracy thriller named Art Bell? Really?
Beth's co-worker Raj Singh shares his name with an Indian general in World War Z. Given that Orphan Black is a sci-fi series, this may or may not be intentional.