Sociology is more tenuously connected - psychology and sociology are fundamentally different fields, and while there is some relation in both studying humans, the methods and object of study differ. Beyond those mentioned however, Maths is usually valued and useful for prospective Social Scientists, including Psychologists, as statistics is a core part of analysing Psychological data, and the calculus covered forms the basis of formal mathematical statistics (although this is arguably beyond the scope required for Psychology, having a strong background in maths is never bad if you're having to use it).
I want to study psychology at a level but i need another two subjects that complement it. I was think about doing Philosophy, Sociology Or Biology. Any opinions?
If you wanted a very psychology based career then I would suggest maybe considering chemistry too. Universities tend to like bio and chem together.
Sorry if this wasn't very helpful.