The original language of Alice's Adventures in Wonderland is English.
Lewis Carroll wrote the novel in English under his pen name; his real name was Charles Lutwidge Dodgson. Macmillan published the first edition in 1865, with illustrations by John Tenniel. The book belongs to the tradition of Victorian English children's literature, although its logic puzzles, parodies and wordplay also made it influential far beyond children's fiction.
English matters especially because Carroll's humor often depends on sound, spelling and familiar English poems. Translators must replace or explain jokes such as the parody poems and the puns spoken by characters in Wonderland. Latin, German and French appear as references or possible alternatives within the story's cultural setting, but none is the language of the original novel.
A related curiosity is that the tale began as an oral story for Alice Liddell and her sisters before Carroll expanded it into the published book. The manuscript version was titled Alice's Adventures Under Ground, while the familiar printed title is Alice's Adventures in Wonderland.