The motion, which passed by 1,136 votes to 70, called on the Scottish Government to launch a review of working practices in Scotland, including the “possibility of a four-day week”.
Employment law is currently still controlled by Westminster, however, meaning any policy designed to reduce weekly working hours could only be enforced by an independent Scotland.
Speaking in favour of the motion, SNP member Lee Rob said a 32-hour working week with no pay reductions would be the “ideal model”.
He said that employees who work a four-day week are “happier, healthier, more productive, less likely to take time off sick and less likely to be burned out by the end”.
“Everyone’s lives revolve around their jobs, and if we can promise that independence will make that arrangement just a little bit easier, then Yes starts to look like a more tantalising option on the ballot paper to those who otherwise might not have been persuaded,” he added.
Joe Ryle, of the 4 Day Week Campaign welcomed the motion, stating that the employment reform would “dramatically improve people’s lives”.
The vote comes after Labour’s landmark decision to back a four-day working week in their manifesto at the 2019 General Election.
Then-leader Jeremy Corbyn promised to reduce full-time weekly work to 32 hours within a decade, and to set up an independent Working Time Commission.
Scottish Conservatives called the SNP’s proposal “ludicrous” and “nonsense”, claiming the policy would cost £2.5bn a year to put into practice.
But in July this year, polling conducted by Survation found that Scots were more likely to support the introduction for a four-day working week than people in the rest of Britain.
The study said 70 per cent of people north of the border back the more flexible working approach, compared with 63 per cent across the UK on average.
The Scottish figure is higher than England and Wales, although lower than the 75 per cent in Northern Ireland, according to the poll of more than 2000 UK adults commissioned by the Autonomy think tank.