What is a good multicultural school motto?

“Educate the world.”
“Education makes the world go ‘round.” (This really works only if your logo is circular.)

Strength in Diversity

“I only did it for the money, our school actually blows”

Schooling For All.

We Are All Human

Are you in the US? Maybe incorporate “Melting Pot” into the motto, borrowing from what we say about the country.

Or, “United Schoolname” or, “United schoolmascot.” Similar to United States, United Earth (Star Trek), etc.

“One School United.” And, use “ONE” when you only have a small space. My university uses One on some things. Or, they did a few years back anyway.

All for one and one for all.

@janbb except for the Borg and two Klingons over there in the corner

Another brilliant suggestion from yours truly: “Divided we stand, together we brawl.”