As the key figure pushing for another independence referendum, her resignation could be seen as a huge blow to the Scottish independence movement.
She added that her stepping down “frees the SNP” on the issue of Scottish independence “to choose the path it believes to be the right one without worrying about the perceived implications for my leadership”.
The First Minister has been mired in controversy in recent months as her Government sought to push through gender reforms, only for them to be blocked by Westminster.
She has also faced a row over the housing of transgender prisoners in women’s facilities.
Ms Sturgeon said her decision to stand down was not a “reaction to short-term pressures”.
Her departure will immediately raise Labour hopes of seizing a slew of Scottish seats at the next General Election, expected in 2024, and gaining an overall majority.
There are several possible candidates to take over, including the Deputy First Minister, John Swinney.
Ms Sturgeon appointed Mr Swinney as her deputy in 2014.
He previously served as Finance Secretary from 2007 to 2016 and the Education Secretary from 2016 to 2021.
Another potential candidate is the current Health and Social Care Secretary, Humza Yousaf.
Kate Forbes, who has served as the Secretary for Finance and Economy since 2021, is also in the running.
In 2020, she delivered the Scottish Budget, becoming the first woman to do so.
Keith Brown, the depute leader of the SNP, said Ms Sturgeon “has given her working life to the cause of independence” and was an “outstanding leader”.
“Nicola Sturgeon has given her working life to the cause of independence,” he said. “Thank you for all you have done, and will do in our campaign to win independence for Scotland.”
Ms Sturgeon took over from Mr Salmond, her mentor, but fell out with him spectacularly over the handling of sexual harassment allegations made against him, which he always denied.
In 2019 Ms Sturgeon referred herself to an independent ministerial ethics body after admitting that she had a secret meeting and subsequent phone call with Mr Salmond about the allegations against him.
More than two years later the report concluded that Ms Sturgeon did not breach the ministerial code.
Her party will meet next month to discuss treating the next UK election as a “de facto referendum”, with more than 50 per cent of the vote being considered a mandate to begin negotiations for Scotland to become an independent country.
The SNP, which runs the Scottish Parliament with the Greens, has 45 MPs at Westminster.
