The only philosophy ideology I have come across that advocates this specifically is Ayn Rand's *Objectivism*. Although I have studied it in detail I don't happen to agree with it and I warn you it is highly controversial. I'll probably get lambasted by someone, pro or con, for just mentioning Ayn Rand here! 

Search online for "The Virtue of Selfishness", which is the title of one of her books, for more info.

You may also be interested in *Utilitarianism* which "...accepts as the foundation of morals utility, or the greatest happiness principle, holds that actions are right in proportion as they tend to promote happiness, wrong as they tend to produce the reverse of happiness."

However there are discussions and papers you will find online that suggest Utilitarianism could be a form of selfishness. The argument seems to stem from the question "happiness for who?" 

Friedrich Nietzsche also espoused selfishness, most notably in his book *Thus Spake Zarathustra*.