The sexual orientation of a person named Sid would depend on the individual's own identity and preferences. Without specific context regarding which Sid you're referring to, it's impossible to determine if he is straight or not. Sexual orientation is personal and can vary widely among individuals.
Sid Bream is a devoted Christian, married and straight. He is the father of three sons and an adopted daughter. For anyone to suggest that he is gay is criminally libelous. I know him personally and can vouch for this answer. Grow up.
Sid Hatfield went by Two-Gun Sid, and Smilin' Sid.
Gary Oldman, who plays Sid in "Sid and Nancy" was given Sid's real necklace by Sid's mom. He wears it in the film too.
Sid Conrad's birth name is Sid Levington Conrad.
Maria Sid's birth name is Maria Charlotta Sid.
Sven Sid's birth name is Sven Olof Sid.
Sid Gordon is 5' 10".
Sid the Sloth was voiced by John Leguizamo.
Sid Eudy goes by "Psycho" Sid Vicious, and The Millennium Man.
Sid Luckman is 6'.
May will get mad at Sid.
Pascal Sid is 185 cm.