The First Minister publicly apologised to an SNP staff member subjected to an “unwanted sexual advance” from Patrick Grady, the MP for Glasgow North, and offered to meet with the victim to say sorry in person.
In a damning rebuke to her own MPs, she said a leaked audio recording suggested they showed more concern for the perpetrator than for the victim.
And faced with a barrage of questions about sexual misconduct and the handling of complaints at First Minister's Questions, Ms Sturgeon confirmed the outcome of investigations into complaints made against Scottish ministers would be published in future.
Mr Grady, 42, was found by an independent panel to have touched and stroked the neck, hair and back of a colleague 17 years his junior at a social event in 2016.
He was suspended from Westminster for two days.
Audio was subsequently leaked of a meeting of the SNP group at Westminster, in which Mr Blackford could be heard saying he was “very much looking forward to welcoming Patrick back into the group next week”, and encouraging fellow MPs to offer “as much support as possible”.
Mr Blackford later apologised for the distress caused to the victim, who says his life has been made a “living hell”.
The staffer called Mr Blackford's statement a “non apology and a bit of a cop out”.
Speaking to the BBC, he said it “seems like the SNP under Ian Blackford in Westminster hasn’t learned a thing, and they're still trying to close ranks and discredit the victim by not really addressing any of the issues”.
The victim said “nobody can really seriously believe they’re going to make improvements to the procedure, as long as Ian Blackford’s still in post”.
In an interview with STV, Mr Blackford was asked six times if it was permissible for a “sex pest” to be an MP. He refused to directly address the question.
He said he had a duty “to make sure that any complainer – in this case, in all cases – is fully supported”, adding: “I believe that I've done that but I will of course as SNP Westminster leader see what learnings have to come out of this.”
Scottish Conservative leader Douglas Ross raised the victim’s comments at First Minister’s Questions.
Ms Sturgeon said: "The recording of the Westminster group meeting I think reveals part of what was wrong in that case.
"Indeed some of the individuals who were recorded at that meeting have already said this themselves.
"It demonstrated – and I wasn’t at the meeting, so whether this is an accurate overall reflection of discussion, I can’t comment on – but what I have heard suggests that more concern was shown for the perpetrator of this behaviour than was shown for the victim of it.
“I think that is utterly unacceptable and that is something I will be very clear about.”
Told that it was the victim’s plea to hear more from the First Minister about the case, Ms Sturgeon said: “I have already written a message that said sorry directly to them.
"I have also confirmed my willingness to meet directly and personally with the victim in this case.
"When, as I hope it will, that interaction takes place I will say sorry in person.
"It’s not my behaviour that was investigated, but I’m leader of the SNP and I take that responsibility very seriously.”
Ms Sturgeon said Mr Grady’s behaviour was “wrong” and insisted: "I take these issues very seriously. It is incumbent on me to do so.
"These issues are not unique to the SNP. All parties have faced these issues and at times all parties have been criticised for their handling of these issues. All of us have lessons to learn.”
Mr Ross said the victim had been “badly let down every single step of the way by the SNP”.
Speaking after FMQs, he said: “Ian Blackford must go, so that a clear message is sent that sexual harassment will not be tolerated, and any victims who come forward will be believed and supported.
“But this is also bigger than just one man. This is a deep, systemic problem in the governing party. It is an all too familiar tale for victims within the SNP.”
Asked if she still had confidence in Mr Blackford, Ms Sturgeon told journalists: “Yes, I do.”
Earlier, Scottish Labour leader Anas Sarwar criticised the Government over its previous refusal to make the outcome of complaints against ministers public.
Former SNP minister Fergus Ewing was reportedly the subject of a bullying complaint, but the outcome of this is unknown.
Ms Sturgeon said the Government was “limited in terms of what we can publish by legal requirements, data protection and confidentiality issues”, adding: “That is not a situation that I am comfortable with.”
She said she had now sought further advice on finding ways to publicly report the outcome of complaints.
Ms Sturgeon said: “The advice I have now only very recently had is that while we cannot apply this retrospectively, there is a way to do that in relation to future complaints.”
She said this would involve changes to the ministerial code and the complaints procedure.
A spokesman for the First Minister was later unable to say when this advice was received, what changes would be made and when they would come into effect.
He also said he did not know what legal constraints currently prevent the publication of findings.
Mr Sarwar said: “I welcome this move – but it is convenient that it will apply only to future investigations and not previous investigations.
“Legal experts are clear that there is not a case for the Government to hide behind GDPR when it comes to these complaints.
"It is perfectly reasonable to ask the Scottish Government to make clear the outcome of investigations into ministers.”