Sample letter of apology to teacher

Dear {Mr./Ms. Last Name}

I am very sorry for what I {said, did, etc…} the other day. In hindsight, my {behavior, actions, etc…} were extremely childish, disruptive and disrespectful to you, my peers and the school.

You can expect better and more appropriate behavior from me in the future. I have learned from this experience and understand that a certain level of refrain and professionalism is expected of me in the classroom.

I recognize your dedication to education and your commitment to instill in me the knowledge I need to succeed. I hope our relationship is undamaged from my actions and that I can continue to learn and grow under your guidance.

Sincerely,
{Student}