The party is planning to mark "Brexit Day" with a rally in Glasgow, where it will relaunch its campaign for independence and also make clear a separate Scotland should be part of the EU.
Ska Keller, the president of the Greens in the European Parliament, will join Scottish Greens co-leader Patrick Harvie for the event on Friday January 31.
Mr Harvie said it was "outrageous and undemocratic" that Scots were being denied a second independence referendum at a time when they were being taken out of Europe against their wishes.
Calls for a fresh ballot on Scotland's place in the UK have been mounting since the UK voted for Brexit in 2016 - with almost two-thirds of voters north of the border supporting Remain in the referendum.
Conservative Prime Minister Boris Johnson recently refused Nicola Sturgeon's call for Holyrood to be granted the power to hold a referendum.
Mr Harvie said: "In 2014, the Better Together campaign told the people of Scotland that No meant we would remain as members of the European Union.
"Yet here we are just over a week from being dragged out against our will and the likes of Ruth Davidson and Willie Rennie who led that campaign don't even have enough integrity to offer an apology.
"It's now clear that we'll be ripped out on the 31st, losing all our rights as EU citizens.
"We'll be denied the right to move, live, love and work in 27 other EU countries.
"Our EU friends and neighbours here fear for their futures in these uncertain times.
"In such circumstances it's outrageous and undemocratic that we are denied a say over our own future.
"The people of Scotland are sovereign, only we have a right to decide our future."
He added: "It is so important in these dispiriting times that we don't let go of hope.
"The people of Scotland deserve better and as we relaunch our Green Yes campaign we will offer a positive vision for Scotland's future - showing how we can make the most of our potential as a small European nation.
"In that spirit I am absolutely delighted that my colleague Ska Keller will be joining us in Glasgow on Brexit Day.
"Greens across Europe recognise that Scotland's future is a matter for the people of Scotland to determine and should we choose to become independent I am confident that our European family would be rooting for us to rejoin the EU as quickly as possible."