The speaker in the poem "Upside Down" by Alexander Kushner is a boy. The central character of the poem, called Upside Down, is portrayed as a boy who behaves in an eccentric and absurd manner, making everything upside down. He is a jester-like figure who acts disorderly, causing people to laugh at him and consider him a misfit in society. The poem provides a humorous yet sympathetic portrayal of this boy, emphasizing his social and mental struggles and society's reaction to his behavior. The poem's perspective is from the boy's experiences and actions, clearly indicating that the speaker is a boy rather than a girl.