The University and College Union (UCU) said the rushed timetable for compulsory job cuts, with the first staff due to leave at the start of November, means alternative options for savings have not been sufficiently explored.
It warned that remaining staff would be left with higher workloads and less contact time with students who would be taught in bigger classes at the university, which is based in Edinburgh but also has campuses in Orkney and the Scottish Borders.
The ballot opens on Tuesday September 29 and closes on October 20.
UCU said 400 members are being balloted including lecturers, research and computing staff, administrators, librarians and other professional staff.
The union’s Scotland official Mary Senior said: “This decision to cut 130 jobs at Heriot-Watt University will add to the worry and upset among staff and students.
“The news comes at a time when staff have worked tirelessly to keep the university running during the Covid-19 crisis and when the chances of finding other work will be hard.
“That these cuts come so soon after jobs losses in 2017 raises questions about the university’s management and whether managers are using the Covid crisis as a smokescreen for unjustified job cuts.
“UCU is open to negotiation and consultation to avoid compulsory job cuts. We urge the university to work with us to identify alternative savings, not rush through job losses at this difficult time.
“However, we are clear that members need to show their strength of feeling against these job losses and that’s why we are balloting members for strike action to defend jobs.”
A Heriot-Watt University spokeswoman said: “The global pandemic has resulted in a significant impact on the university’s income. This financial challenge is resulting in the need to make some difficult decisions, and this includes proposals to reduce the number of roles across the university.
“We are committed to finding these through voluntary means wherever possible, either through potential redundancy or other voluntary options such as a reduction in working hours, career breaks and flexible retirement.
“We continue to consider all suggestions for cost savings, and consultation with unions and staff around the proposals for role reductions, which includes a number of externally-funded research roles coming to their natural end, is ongoing.
“No final decisions have yet been made and the programme for voluntary options is currently still open.”