Bill the Lizard is a fictional character appearing in Lewis Carroll's Alice's Adventures in Wonderland.

Introduced in chapter four, Bill is perceived by Alice to be someone who does all of the hard work for The White Rabbit and the denizens of the community. When Alice becomes stuck in one of The White Rabbit's house's rooms from drinking a bottle that made her grow uncontrollably, the rabbit's attempts to get in through the door and window fail. Bill the Lizard is sent to go through the chimney to investigate, since he and another creature have a ladder in their possession. Unwilling to let Bill get through the chimney, Alice uses her now huge foot, which is in the chimney, to kick Bill into the air. He manages to survive the fall thanks to the fellow creatures.

Reappearing in chapters eleven and twelve, Bill is a juror in the trial of The Knave of Heart's supposed theft of The Queen of Heart's tarts. When his pencil squeaks too much on his slate, it annoys Alice to the point that she takes the pencil from him. Not knowing where it went, Bill the Lizard starts using his finger to write, even though it left no mark on the slate. In chapter twelve, he becomes disheveled when the "mile-high" Alice disturbs the jury by messing up the jury box. When Alice puts Bill the Lizard back in his place, he stares blankly up in the sky. Then later, the Queen provides ink for Bill when she spills ink on his face.