- Tho Whos: [singing] The world is a-sittin' on an elephant's nose.
- Female Who: An elephant's what?
- Washer Who: An elephant's nose.
- Cindy Lou Who: What's an elephant?
- [while Horton's clover is being carried away by Quizmo McKwoff]
- Horton: Dr. Hoovey? Quick, Doctor! / Fasten your seat belt! Tie yourself down! / Batten your hatches! Sandbag the whole town!
- Dr. Hoovey: Batten our hatches? I don't understand! / What is a seat belt? We're fresh out of sand.
- Mother Who: Is Horton an elephant?
- Baby Who: No, ma'am, Horton's a pickle.
- Other Baby Who: What's a Horton?
- Tho Whos: [singing to Dr. Hoovey, who they now believe after they have been dropped from the sky] Just tell us what we have to do! / Just tell us and we'll follow you! / We'll save this town, we'll save this world! / Just tell us what we have to do!
- Dr. Hoovey: [spoken] What to do? / I wish I knew!
- Horton: [after attempting to get the Whos to make themselves heard, which fails] Uh, you should've heard *that*, just as clear as a bell. / Everything is going to be... perfectly swell.
- Jane Kangaroo: Hmph, I heard nothing, and *you* didn't either, / And as for my prodigy, *he* didn't...
- Junior Kangaroo: ...Neither!
- Jane Kangaroo: Hmph!
- Narrator: It was Jane Kangaroo, and the small kangaroo in her pouch said:
- Junior Kangaroo: Hmph, too!
- Horton: [after he rescues the dust speck] There. Whoever you are, all your troubles are over. I'll-I'll put you down safe on this comfortable clover.
- Wickersham Brothers and their relations: [repeatedly singing] He's going to be roped, he's going to be caged. Horton the elephant's going to be caged.
- Horton: But, this is incredible. What are you, anyhow?
- Dr. Hoovey: Not what, sir. I'm a Who.
- Horton: A Who? You're a Who?
- Dr. Hoovey: Yes, a Who. Uh, W-H-O. Who. I live here in Who-ville.