ICLEI is a group of grown-ups who work together to make the world a better place to live. They want to help protect our planet by making our cities and towns more friendly to the environment.
ICLEI stands for "International Council for Local Environmental Initiatives". It is a long name, but it really just means they help people who live in cities (like where you live) to come up with ideas to protect things like the air we breathe, the water we drink, and the animals that live around us.
They also help people who work in city government (like the mayor or city council members) understand how to make the city better for the environment too.
So if you see people walking around town with a logo that says "ICLEI", just know that they are working hard to make our world a better place!