The university had pushed most classes online for several weeks, amid a spike in cases across Manchester.
Two of its halls went into lockdown last month following a cluster of infections, with hundreds of students told to self-isolate.
There will be a shift back towards face-to-face teaching from Monday, with up to three hours of in-person activity provided each week for most courses, MMU said.
The decision has been slammed by UCU, with its north west regional official accusing the university’s vice-chancellor of wanting “to undermine the city’s sacrifice, and risk the health and safety of staff and students by urging them to return to campus”.
“Staff have spent the past three weeks teaching online, and the university needs to give them the resources to continue to provide students the best possible remote learning experience under these difficult conditions, instead of rushing to return to in-person teaching,” UCU official Martin Moss said.
He added: “If the vice-chancellor continues to risk the health of staff, students and the local community in this cavalier manner we will have no choice but to ballot our members for industrial action.”
A MMU spokesman said the decision to reintroduce more in-person teaching was in line with advice from local and national public health authorities.
“Most of our teaching will remain online, but we will provide up to three hours of in-person activity each week for most courses,” they said.
“Above all, this reflects the wishes and needs of many of our students, who tell us and the Students’ Union, that they greatly value in-person activity. This supports their mental health and wellbeing and helps them to build a sense of community with other students and the university.”
Evelyn Sweeney, president of the MMU Students’ Union, welcomed the return to face-to-face teaching.
“Students have told us that it helps to create a sense of belonging and personal interaction helps students to build stronger relationships with tutors,” the president said.
“Seeing classmates creates a sense of community and does a great deal to alleviate feelings of isolation and loneliness.”
While most universities have offered blended learning – a mix of online and face-to-face teaching – during the coronavirus pandemic, a handful have decided to shift more classes online as coronavirus infections rose in the local community.
The University of Manchester is not yet planning to return to in-person teaching for most students, but the policy will be reviewed in early November.
Northumbria University and Sheffield University – which have both faced coronavirus outbreaks since students returned – have also decided to teach the majority of classes online, as well as three universities in Liverpool.
Additional reporting by Press Association