Hugh Baird (22) received 1900 votes (41.19%), 616 votes ahead of candidate Hashmatullah Lafraie.
Mr Baird, a fourth-year marketing and management student, and current Critic magazine editor, said he was "ecstatic'' about winning the election.
"I am looking forward to leading an executive that represents the student body and the thoughts and feelings of the student collective.''
Current president Laura Harris did not seek another term.
The voter turnout of 4613 was down on recent years, including 2013 when OUSA called a voter turnout of 5193 the best in a generation.
Current OUSA recreation officer William Guy was elected vice-president.
Lark Hare also ran for president, receiving 1204 (26.10%) of votes.
2017 executive:
President, Hugh Baird; vice-president, William Guy; finance officer, Cody Kirby; education officer, Bryn Jenkins; welfare officer, Danielle Pope; postgraduate officer, Lucy Northwood; international student officer, Max Chan; campaigns officer, Eden Lati; recreation officer, Caitlin Barlow-Groome, colleges officer, James Heath.