Alice McBrearty, 23, admitted to having a four-month fling with the pupil, who she taught at an east London school, earlier this year.
Snaresbrook Crown Court heard McBrearty had kissed the youngster in a classroom and taken him to an Ibis hotel for sex.
A judge was told she also performed sex acts on him in an empty garage, her car and her parents’ East London home.
McBrearty, who pleaded guilty to seven counts of sexual activity with a child while in a position of trust put her head in her hands and sobbed in the dock as Judge Sheelagh Canavan sentenced her on Friday.
Jailing her for 16 months, the judge said she had committed the “grossest breach of trust”.
She said: “You engaged in a full-blown sexual relationship with a 15-year-old child.
“I accept he was consenting – what 15-year-old schoolboy would turn down such an attractive offer?
“I accept you truly believed this was a great romance, you were in love with him and vice versa, and that age didn’t matter. But it did.
“You were supposed to keep him safe, to help him make the right decisions.
“Instead, you helped him make all the wrong ones.”
The court heard the relationship began when McBrearty sent the boy, who cannot be identified, a friend request on social media.