嘿哟 (hēi yō) is a colloquial, onomatopoeic interjection used to express sudden physical effort—like lifting, pushing, or pulling something heavy—or mild surprise or exasperation. Though written with two characters, it functions as a single unit and carries no literal meaning; 嘿 and 哟 individually are common exclamatory particles, but together they form a rhythmic, emphatic grunt often heard in manual labor, group coordination (e.g., carrying furniture), or spontaneous reactions. It’s informal and conversational, rarely found in formal writing.

This expression is deeply tied to spoken rhythm and timing: speakers often use it in sync with movement (e.g., 'Hey-yo!' on the lift), and tone is more about stress and cadence than lexical pitch. It conveys shared exertion or lighthearted frustration—not pain or anger—and is frequently accompanied by body language like grunting, straining, or raising eyebrows. While historically associated with folk work songs, today it appears widely in everyday speech, cartoons, and light-hearted dialogue among friends or family.