Michelle Lynn Dennis, 33, today pleaded guilty in the County Court at Ballarat to two counts of sexual penetration of a child under supervision and one count of sexual penetration of a child under 16.

Dennis committed the offences against two students while teaching at Ballarat High School in 2007.

The former music teacher engaged in the sexual acts outside of the school's grounds.

Dennis, of Sebastopol, was charged with the offences in October, last year, and stood down from Ballarat High School.

She was also suspended from teaching by the Victorian Department of Education and Early Childhood Development.

In August, she was ordered to stand trial on 26 charges after a one-day committal hearing at Ballarat Magistrates Court.

At this time, Dennis pleaded not guilty to all of the charges.

Dennis appeared in court this afternoon with a male supporter.

Her plea hearing will be held before Judge Susan Cohen on November 17.