The first speaker in 'The Wizard of Oz' is LEO, a three-letter name. LEO is the gatekeeper of the Emerald City and is the first character to speak in the movie. He is the one who greets Dorothy and her friends when they arrive at the gates of the city. He is also the one who informs them that they must see the Wizard before they can enter. LEO is an important character in the movie and his role is essential to the plot.