Bernadette Smith, 35, had quit her job as a history and English teacher at Bannockburn High School last month after allegations that she had a fling with a 16-year-old student.
However, after meeting officials from the Educational Institute of Scotland (EIS) she later retracted her decision to leave, prompting an inquiry into her alleged conduct by senior council officials.
It emerged yesterday that after the inquiry Ms Smith was dismissed for "gross misconduct".
The married mother-of-three was held by police on September 22 over the claims, part of which allege she and the pupil engaged in sexual activity in a public park.
She appeared in court from custody on September 23 to answer the charge against her.
She denied the single charge that between September 13 and 20 at an address in Cowie, Stirlingshire, and at Callander Park, Falkirk, while in a position of trust she engaged in sexual activity with the pupil. It is alleged this involved kissing him and also lying on a bed next to the boy partially clothed.
Last week Stirling Council's head of education David Leng chaired a disciplinary inquiry into the matter.
A council spokesman said: "It heard allegations against a teacher at Bannockburn High who had recently been sus- pended and the outcome was that the employee should be dismissed on grounds of gross misconduct."
The spokesman said the General Teaching Council will be informed of the decision.
Allegations against the teacher surfaced in the days before her court appearance.
Bannockburn High was made aware of the claims on September 19 after it was contacted by the teenager's parents. Ms Smith was asked to attend a meeting at the school the next day where she was informed of her immediate suspension pending an inquiry.
She verbally resigned but later refused to confirm her resignation in writing.
Police were informed of the allegations and tracked the teacher down to an address in Stirling. It is not believed to be the address she shared with husband Brian and their children.
On the day of the court appearance, the school released a statement to parents assuring them that classes were operating as normal and support was also being offered to staff and pupils.
However, parents of pupils criticised education officials after hearing of the allegations in the media before they were told by the school.
Headteacher Tom Black sent text messages and letters to parents on the afternoon of Ms Smith's appearance in court.
Ms Smith, of Denny, near Falkirk, pleaded not guilty when she appeared in court. Her solicitor, Harry Coughlan, said she would challenge the aspect of the charge which asserts she was the boy's teacher in a position of trust.
She will appear next for a pre-trial hearing in December, prior a summary trial before a sheriff in January.