The National Union of Students (NUS) said it was supporting the UCU.
Scotland president Justine Pédussel said: “The national student movement stands in solidarity with all tertiary education staff currently striking or taking industrial action across Scotland.
“Students only thrive when staff have secure, well-paid positions.
“Any temporary disruption is a small price to pay for a more secure future for education.”
Prof Mathieson said the university was “extremely disappointed” by the decision to strike.
He told the BBC’s Radio Scotland Breakfast programme: “I have enormous sympathy with our students and it really irritates me that they are being weaponised in the way that they are by UCU.
“And UCE know that they are targeting students. Of course they can say that they think students are on their side because, I was a student once and we were all anti-establishment, and of course you’re going to blame the establishment.
“But the fact is that the situation in the university is not sustainable and we have to do something about it.
“Otherwise future generations of students – whether they are Scottish, English or international – won’t be able to benefit if the university is not in a financially resilient and sustainable state.”
The principal said the decisions the university were taking would maintain its “position as a world-class institution with a vital role in Scotland’s economic and civic life”.
The strike comes just a week after lecture staff at the University of Dundee started five weeks of strike action over compulsory redundancies.