The ex-SNP leader has been an MSP since 1999 and said representing Glasgow Southside had been “an honour beyond words”.
In a post on Instagram, Ms Sturgeon added: “However, I have known in my heart for a while that the time is right for me to embrace different opportunities in a new chapter of my life.
“I have therefore written this morning to SNP members in my constituency informing them that I will not be seeking selection for next year’s Holyrood election.”
Ms Sturgeon thanked past and present constituents for the “trust” they had placed in her.
She added: “Being your MSP has been my privilege and I will continue to represent you to the best of my abilities until I step down next year.
“To Southside SNP members: your support, loyalty and friendship, through thick and thin, has meant more to me than you will ever know. You are the best of the best.
“To SNP members across the country: I may be leaving parliament, but I will be by your side every step of the way as we complete our journey to independence.”
Ms Sturgeon joined the SNP when she was a teenager and worked as a solicitor before her election to the Scottish parliament in 1999.
She succeeded the late Alex Salmond as first minister of Scotland after his resignation in 2014 following the results of the Scottish independence referendum.
Ms Sturgeon was the first woman to hold both positions of SNP leader and first minister, and was the longest-serving first minister in Scottish history until her shock resignation in 2023.
During her time in charge, she led Scotland’s response to the COVID pandemic, and was responsible for setting up the nation’s devolved benefits agency.
When she stepped down, Ms Sturgeon denied controversy surrounding the Scottish government’s Gender Recognition Reform (Scotland) Bill had played a part in her decision.
In the weeks leading up to her departure there had been a public outcry over transgender double rapist Isla Bryson being housed in an all-female prison before being moved to the male estate.
This breaking news story is being updated and more details will be published shortly.
Please refresh the page for the fullest version.
You can receive breaking news alerts on a smartphone or tablet via the Sky News app. You can also follow us on WhatsApp and subscribe to our YouTube channel to keep up with the latest news.
