The First Minister insisted she would "initiate the process necessary to enable a referendum before the end of 2023" in the course of next year.
She also said her party would set out its fresh case for leaving the UK, outlining the "opportunities and advantages", but also the "challenges".
Scottish Conservative leader Douglas Ross insisted it was a “disgrace that on the same day as the First Minister is talking about the possibility of introducing new restrictions to combat the Omicron variant, her focus is once again on breaking up the UK”.
The UK Government has repeatedly said it will not agree to a second referendum.
But addressing Prime Minister Boris Johnson directly on Monday, Ms Sturgeon said: "If you have any respect at all for democracy – and if you have any confidence whatsoever in your argument against independence – you too will let the people decide."
The First Minister's comments came shortly after she held a televised briefing following cases of the Omicron variant being identified in Scotland.
In a speech on the last day of the SNP's online conference, Ms Sturgeon called on delegates to harness a spirit of solidarity "as we prepare for a winter that might be tougher than most of us have ever experienced".
But Ms Sturgeon insisted she "would not be discharging my duty to the people of Scotland if I did not seek to keep the promise on which we were elected – to offer the people of Scotland the choice of a better future through independence".
She added: "Next year, Covid permitting, as we emerge from winter into spring, the campaign to persuade a majority of people in Scotland that our future will be more secure as an independent nation will resume in earnest.
"In the course of next year, I will initiate the process necessary to enable a referendum before the end of 2023.
"And just as importantly, our party will set out afresh the positive case for independence. We will outline the opportunities and advantages that independence will open up.”
She continued: "We will also be candid about the challenges the transition to independence will present, and set out clearly how we can and will overcome them.”
The First Minister used her speech to accuse Mr Johnson of “actively eroding the power of our democratically elected Scottish Parliament”.
Mr Ross said: “The people of Scotland will have sighed with dismay – but not disbelief – that Nicola Sturgeon’s response to the serious new Covid strain is to reaffirm her commitment to holding another divisive independence referendum within two years.”
Scottish Liberal Democrat leader Alex Cole-Hamilton said Ms Sturgeon’s speech “had almost twice as many references to independence as it did to the health service”.
He added: "If only the energy that she and her party put into trying to leave the UK was poured into health, education and the climate emergency.”
Pamela Nash, chief executive of pro-UK group Scotland in Union, said it was “yet another tired speech from a First Minister keeping Scotland on pause while she obsesses about the constitution”.