Events held by a school, such as sports day, cultural festivals, entrance/graduation ceremonies, etc.
来週は学校行事で全校生徒が体育館に集まる。
Next week there is a school event, and all students will gather in the gymnasium.
文化祭は毎年の学校行事の中でも特に盛り上がる行事だ。
The cultural festival is one of the most exciting school events every year.
学校行事の準備で放課後も生徒たちが残って作業している。
Students are staying after school to prepare for the school event.