Camilla, known as the Duchess of Cornwall outwith Scotland, succeeds Lord Wilson of Tillyorn, who stepped down at the end of December having served since 1997.
The Duchess was elected unopposed by the university's graduate body, the General Council, and will act as an ambassador for the university.
Her role comprises ceremonial duties including awarding degrees to graduates at the end of each year.
Professor Sir Ian Diamond, principal and vice-chancellor of the university, said: "I am delighted that the Duchess of Rothesay will be our new chancellor.
"Lord Wilson was a wonderful champion for the university both here in the UK and abroad, and we know that the Duchess will be a brilliant ambassador for the international centre of excellence in learning that we are proud to be.
"We have very much enjoyed the Duchess's visits to our campuses and the huge enthusiasm and interest she has shown in meeting our students and staff, and hearing about their work and achievements.
"I look forward to formally welcoming Her Royal Highness to the university team."