A YouGov poll for The Times found the First Minister's personal ratings have slumped from +50 in August last year to +12.
However, she is the only Scottish leader to have a positive rating.
Scottish Labour’s Anas Sarwar is on -1, while Douglas Ross of the Conservatives scored -28.
The ratings come ahead of the SNP's virtual party conference, which starts on Friday and runs over the weekend.
YouGov polled 1,060 over-16s between November 18 and 22 for the survey.
A separate poll for the pro-UK group Scotland in Union also found a majority of people oppose Ms Sturgeon's preferred timetable for another independence referendum.
The Survation poll found 54 per cent are against another vote within the next two years, up two points since September.
Pamela Nash, chief executive of Scotland in Union, said: “Ahead of the SNP conference, this poll confirms that Nicola Sturgeon’s priorities are not the priorities of the people of Scotland.
“A majority do not support her timetable for a divisive second referendum and growing numbers of voters favour remaining part of the UK.
“She should drop plans for another referendum and focus on what really matters – the NHS, Covid recovery, jobs, and the climate emergency – rather than obsess about her negative campaign to divide Scotland’s communities.
“Scotland has a positive future as part of the UK, where we bring people together, look outwards to our friends and neighbours, and leave no community behind.”
Writing for The Times, polling expert Professor Sir John Curtice, of Strathclyde University, said Ms Sturgeon "is at risk of looking like a politician stuck in second gear".
He said: "For while she may still be Scotland's most popular politician (albeit not as popular as earlier in the pandemic) who leads by far and away Scotland's most popular party (albeit one dependent on the Greens for its Holyrood majority), there is little sense of progress towards its ultimate goal of independence."
However, Sir John said there was “no sign of any electoral challenge to the grip of the nationalist movement on the Holyrood chamber”, while the SNP “appears well placed to maintain its dominance of Scottish representation at Westminster”.