An SFRS spokeswoman said: “We were alerted at 1.47pm by an automated fire alarm system from Larbert High School.
“Operations Control mobilised three appliances to the scene. Firefighters extinguished an electrical fire within the premises.
“There were no reported casualties.”
High school pupils are back in school full-time, following a blended model involving online learning and face-to-face teaching.
A Falkirk Council spokesman said: “A small fire appears to have started in a washing machine in the school and the fire alarm was activated.
“All staff and pupils were evacuated quickly and safely and the fire was soon extinguished.
“Although the room where the fire started will be out of commission pending repair, the school will reopen tomorrow as normal.”