|Leo in normal pose|
|Relatives||Annie (little sister)|
|Likes||Helping his friends|
|Voiced by|| Jesse Schwartz|
Harrison Chad (singing voice)
|First appearance||Ring Around the Planet|
|Previous appearance||Little Elephant's Big Parade|
Leo's Full name is Leonardo, but he likes being called Leo. It was confirmed on the old Little Einsteins Website.
Leo is a human. He has red hair and green eyes and eyeglasses. Leo is the leader of the Little Einsteins. He pilots Rocket. He is Annie's big brother and his main talent is conducting. His most precious object is his conductor's baton. He uses the baton to conduct the music to the right beat. In most episodes, if his rocket wanted to go superfast, he will start slow, then become fast, and finally the beat becomes presto(superfast) He is a trustworthy.