It took the jury three and a half hours to reach the verdict.
Scott had pressed himself against a Kapiti Coast District Council employee at a morning tea following a council meeting in April last year.
During the trial, Scott's penis was measured by a doctor to determine if it was the same length as what the victim felt pressing into her.
The measurement was suppressed.
In her closing address to the jury, Crown prosecutor Kate Feltham said it could not have been Scott's wallet the employee felt, because he kept his wallet in his right pocket not the left, which is the area in which the complainant said she felt the penis.
"Now whether she felt his penis or whether she felt something else, I suggest doesn't actually matter because his actions in grabbing her, holding her and thrusting himself into her were what made it indecent."
Scott's lawyer had applied for a discharge without conviction.
Judge Hobbs said he couldn't grant that, because the offending fell into the "moderately serious" category.
"It was brief, and over clothing. However, there are aggravating features that must be acknowledged.
"You were at the time an elected public official. You do hold a position of power at council.
"Your offending involves a breach of trust in the workplace, which is a place where all staff are entitled to feel safe from such behaviour, particularly from those who hold positions of power.
"You are not entitled to any credit for remorse, as you have shown none.
"Looked at in isolation the offending itself is at the lower end of the scale.
"However, it cannot be divorced from the circumstances around it. It happened in an environment where you held a position of power."
Judge Hobbs said that while the conviction meant Scott would lose his position as a councillor, that was a consequence of the offending.
He said that elected officials could not be immune from the consequences of offending while in office.
Outside court, Scott said that he would launch an appeal.
A spokesperson for the Kapiti Coast District Council said Scott would be placed on a leave of absence.
"Councillor David Scott has the right to an appeal. Until the appeal period has expired or any subsequent appeal is heard, he will be on a leave of absence.
"During this time he cannot act as a councillor.
"The Local Government Act sets out what happens when a councillor is convicted of a crime that carries a maximum penalty of more than two years' imprisonment.
"Subject to any appeal, Councillor David Scott will be disqualified from office. If this happens before 12 October there will be a by-election."
After the jury verdict in May Scott said he would refuse to stand down from his position as Kāpiti Coast district councillor.
The 71-year-old said he had received more than 100 messages of support from ratepayers wanting him to remain at his post.
He said the case was the worst thing that had happened to him in his life.
