Stacy Schuler, 34, was released Tuesday after serving nearly 13 months of a four-year sentence, the Cincinnati Enquirer reported.
She was convicted in October 2011 of 16 counts of sexual battery and three misdemeanor counts of serving alcohol to minors.
Schuler's attorney, Charlie H. Rittgers, said the judge considered a year in prison, loss of Schuler's teaching position and having to register as a sex offender as punishment enough.
Prosecutors had argued against her early release, noting Schuler had already received a break in sentencing.
One of the victims testified Tuesday that "most people in society feel that it's every 17-year-old male's fantasy to sleep with their teacher," but for him it had turned into "a nightmare that I'm still living in today."
The mother of one victim said the time Schuler had spent in prison amounted to about three weeks per count.
"It is appalling and I strongly object," she told the court. "Our lives have been ripped apart, torn upside down."
Warren County Judge Robert Peeler said he had received a number of letters of support for Schuler.
He ordered her to five years of probation and to undergo drug and alcohol treatment, psychological treatment and counseling for sex offenders.