Weve had three seasons now of getting to know Felicity Smoak, including a flashback episode that introduced us to her Gothic college years, and have on a couple of occasions met her rather more extroverted mother Donna. The one piece of the puzzle missing is her father, who left when she was a child. Weve heard a couple of pieces of information about him though, which make his identity all the more mysterious, and increases the desire to see him appear on the show. First of all, he has an extremely high-intellect, which is obviously where Felicity gets it from (no disrespect, Donna). Secondly, he is a criminal. Oh, and David Ramsey (who plays Diggle) said at a convention: When you find out who Felicitys father is, youll know why she can beat anyone (mentally). So, a super intelligent criminal whose appearance would be a bit of a big deal? It could well be a high-ranking H.I.V.E officer, with the organisation set to appear next season, but the more prevalent theory is that itll be their leader. Given he is set up to be the main villain of season 4, that would make for some serious daddy issues.