Mike Johnson said the elite Fife institution had outreach programmes which connected with local communities.
Recent figures showed that the number of 18-year-olds from Scotland's poorest areas going to university was down.
Mr Johnson said a good university needed "diversity of thought" from its "diversity of students".
The admissions' director was speaking to BBC radio presenter Bill Whiteford who was hosting Thursday's Good Morning Scotland programme from St Andrews, Scotland's oldest university.
Mr Johnson said: "We meet our funded places allocation with Scottish students, we cannot go above that cap but we always meet that number in terms of Scottish students.
"What we want to see is the diversity of the student, wherever that student comes from.
"It shouldn't be seen as some charitable venture at universities - this is about the diversity of a student bringing diversity of thought, we want many world views.
"When students are in tutorials we want them to come from different backgrounds, this is good for universities, there is no doubt about that."
The Scottish government has placed a major focus on cutting the attainment gap between rich and poor, and increasing the number of Scots from the worst-off communities making it to university.
However, some politicians and education experts believe the cap on funded university places needs to be lifted if the system is going to target poorer students without impacting on the wider student population.
Convenor of Universities Scotland, Andrea Nolan, told the programme it was important to give "as many opportunities as we can to people who we believe have the potential and the ability to succeed".
She explained "In Scotland we have a fixed number of places for Scottish and EU domicile students and as we seek to widen access to people from communities that are underrepresented at universities that is going to put pressure in a fixed system."
Ms Nolan said lifting the cap on places was one way of "expanding the system".
She added: "There are other ways where we can work more efficiently with our colleagues in the college sector, but we are keen to have the opportunity available to those attending higher education, if that is the right pathway for them. So that may involve expanding places."
Ms Nolan said universities were keen to talk with the Scottish government about ensuring that "everybody who has the potential and ability to succeed at university gets that opportunity".
Education Secretary John Swinney said work was under way to improve access to education for those from the most deprived backgrounds.
He told the BBC: "We have to work collaboratively with the universities, with other players in the education system to make sure we strengthen the attainment of young people and ensure that young people are able to have a wide choice of what destination they want to pursue."
The head of admissions at the University of St Andrews said it had a good "student diversity" policy without having to be a "charitable venture".