Workers and the jobless will march from George Square to Glasgow Green, as thousands more demonstrate in London and Belfast.
Sacked disabled workers from Remploy factories will lead the march along George Street, into High Street and past Trongate, in an action set to attract protesters from across the country.
Up to 10,000 people are expected on Saturday in support of a "Future that Works" campaign which is trying to halt the austerity measures.
Dave Moxham, deputy general secretary of the STUC, said 7000 demonstrators were expected from 11am in George Square, where STUC general secretary Grahame Smith, Robin Parker from the National Union of Students, and Sally Foster-Fulton, convener of the Church of Scotland's Church and Society Council will speak from a converted fire engine.
Video footage from a rally in London will be shown at Glasgow Green, where the rally is to start at 12.30pm.
Mr Moxham said: "Austerity isn't working. Our country faces long-term economic problems. But our political leaders have failed to face up to them.
"Austerity has led to a vicious circle of decline with fewer jobs, cuts in public services and a savage attack on the benefits of the most vulnerable.
"Instead of just letting the banks go back to business and bonuses as usual, we need policies that promote new and old industries. This new approach would create jobs, especially for young people.
"It would encourage companies to raise average pay, penalise big bonuses and invest in training and new industries. It would crack down on tax evasion by big companies and the super-rich."
Mr Moxham admitted the Coalition won't listen to "any single action" but he and protesters hope a sustained campaign will eventually force them to accept that a change of direction is needed.
Final preparations were under way as dozens of jobless people, students and campaigners head for Glasgow from Stirling on a Youth March for Jobs.
They are backed by Lynn Henderson, Scottish secretary of civil servants union PCS. She said: "Young people will face a bleak future if the Coalition Government is allowed to continue its austerity agenda."