The rail operator had warned ongoing negotiations meant that drivers were not volunteering for Sunday shifts.
ScotRail said it aimed to run two-thirds of its services and buses would replace trains on some routes.
The operator has published an amended timetable listing cancelled services and those with reduced frequency.
On Wednesday, ScotRail said it had offered drivers a 2.5% pay rise and a one-off bonus, and would increase driver numbers.
But Aslef accused the Abellio-owned operator of trying to push new terms and conditions through.
Scottish Trades Union Congress general secretary Grahame Smith said: "It is simply astonishing that significant service reductions are being announced only three months after Abellio assumed control of the ScotRail franchise.
"Their approach to workforce planning and industrial relations appears nothing short of shambolic and contrary to the impression they were anxious to portray during the bid process.
"The Scottish government must now answer serious questions over how service cuts and amateur industrial relations are permissible under the terms of a very detailed franchise agreement."
A Transport Scotland spokeswoman said: "Industrial relations are a matter for the employer and the union.
"It is in the best interests of passengers that ScotRail and Aslef come together to resolve this issue as quickly as possible to avoid unnecessary disruption.
"Keeping passengers informed and ensuring they can plan ahead with confidence in advance is a key priority and people should check the updated timetables on the ScotRail website before they start their journey."
ScotRail have said that although they will be running fewer trains on Sundays, most of the trains that do run will have more carriages.
It claimed this would provide almost the same capacity as was offered by the normal services on every route.
The rail operator has advised customers to plan ahead for the weekend.
ScotRail has cancelled a third of its usual services this Sunday, after pay talks with train drivers' union Aslef stalled.