Paul Hartmut Würdig (born 30 November 1980), better known as Sido, is a German rapper. He interprets his artist name as "super-intelligentes Drogenopfer" (super-intelligent drug victim). It used to stand for "Scheiße in dein Ohr" (shit into your ear), a line from his track Terroarr.
Sido distinguishes himself by using provocative and aggressive lyrics. After his breakthrough with his debut album Maske in 2004, he was always seen wearing a silver skull mask. However, as stated in various interviews, since 2005, he no longer wears the mask.
Würdig's career began in 1997, as one half of duo Royal TS (now A.i.d.S) with B-Tight, both of whom were later signed to the label Berlin hip hop Royal Bunker and then to Aggro Berlin in 2001. As of 2009, Sido is signed to Urban/Universal Music Group.