The Lothian MSP said she would campaign for an elected upper house north of the border, describing Glasgow as "the biggest city of a nation that has just reaffirmed its commitment to keeping our country together? A yes city."
But many were quick to point out that Glasgow was one of only four local authorities to back independence in last September's referendum.
They took to Twitter to blast Dugdale's idea, some criticising it as "crazy", others, too expensive.
Dugdale, who was deputy to ex Scottish Labour leader Jim Murphy until his resignation in May, also criticised the frontrunner in the battle to succeed Ed Miliband.
"Here’s a guy that’s broken the whip 500 times. So how can the leader of the party enforce discipline with that record?” she mused.
The 33-year-old made headlines on Monday with an attack on the Prime Minister for comments he made last week, describing migrants and refugees in Calais as a "swarm".
"When David Cameron described those people trying to enter the UK on the back of lorries heading for Dover as a “swarm”, he got it badly wrong," she wrote in the Daily Record.
"Bees swarm over honey, people looking for sanctuary do not."