Daniel Leamy won a hard-fought contest against incumbent president Liam White by 1208 votes to 1095.
Just over 2300 votes were cast, making it the busiest campaign for OUSA president in many years.
Asked about the renewed interest in student politics, Mr Leamy, 20, said: "I actually think that it’s about the state of the world probably".
"People, students especially, are quite down about the state of the world and want to actually do something. That’s probably caused people to run and then caused people to vote."
Mr Leamy said he ran on a three-point platform of "student housing, cost of living and a student bar".
He said student housing was largely about "getting the compliance issues right", while the proposed "rental warrant of fitness" was something to be discussed at a "higher political level".
A student bar had been discussed for many years, and Mr Leamy admitted some of the suggestions he had seen for it he "didn’t necessarily agree with".
The cost of living was high on the minds of most students, he said.
"We’re looking at trying to get just cheap bulk power discounts for students. We’ve got 20,000 members as an association, so we have the buying power to do something about it."
Mr Leamy, who is studying a bachelor of commerce and finance, said he had enjoyed being the financial executive for this term of the OUSA.
"I understand OUSA as best as anyone could when going to being president, which is really good.
"I know the staff. I know the people around, which is really cool. I know the finances, obviously."
There are busy times ahead for Mr Leamy, including the upcoming OUSA annual meeting, but he said he was mostly looking forward to "meeting lots of new people".
His message for anyone wanting to get involved in the OUSA was simple.
"Just do it. If you think you can make a difference, just make yourself do it.
"Because it takes a big step to put yourself out there."
