Authorities arrested teacher Aimee Palmitessa, 45, on Friday at her home in West Hollywood.
The biology teacher is facing charges of statutory rape of a 16-year old student at the school.
Palmitessa was released on $230,000 bail, according to the Los Angeles County Sheriff's Department.
She was also "immediately" placed on administrative leave, according to a statement released by the school on Sunday.
"We were shocked and distressed to receive the news of these allegations. As always, our primary concern is the safety, health, and well-being of our students. To that end, we will do everything we can to cooperate with the official police investigation."
One neighbor who didn't want to go on camera said Palmitessa and her husband have one child, and they appeared to be a happy couple.
Brentwood School is an elite K-12 coed school in the Brentwood neighborhood of Los Angeles.
It is highly regarded for academics, arts and athletics and is the school of choice for many celebrities' kids. Notable alumni include famous names such as Adam Levine, Jonah Hill and Patrick Schwarzenegger.