Sturgeon said she anticipates that a vote will take place “in the earlier part” of the next Scottish parliament, which begins next year.
“The referendum for a whole variety of reasons should be in the earlier part of the next parliament,” she said.
Her Scottish National Party (SNP), which has formed the government since 2007, is expected to perform strongly in elections to the Scottish parliament in May.
This would give her government a mandate to hold another referendum on independence.
Scots voted 55-45 percent against independence in a 2014 referendum.
British Prime Minister Boris Johnson says the first referendum was decisive and should be respected.
His government has said there should not be another independence referendum in the near future.
If Sturgeon wins the election in May, Johnson will have to make a decision whether to refuse a referendum and thus allow Scottish discontent to simmer or allow a referendum which could break apart the union.
The UK and Northern Ireland includes England, Northern Ireland, Scotland and Wales.
Britain voted 52-48 to leave the European Union in a 2016 referendum. Scots voted 62% to 38% in favor of remaining in the EU.