# I'll be a monkey's uncle

idiom

Source: https://englishreference.com/idiom/ill-be-a-monkeys-uncle
Updated: 2026-08-10

## Meaning

Often preceded by well: expressing complete surprise or disbelief.

## Examples

- Well, I'll be a monkey's uncle, you actually won the lottery.
- I'll be a monkey's uncle, the cat and dog are finally sleeping together.
- When my old friend walked into the room after ten years, I said, "Well, I'll be a monkey's uncle!"
- If that broken old car actually starts on the first try, I'll be a monkey's uncle.
- Well, I'll be a monkey's uncle; I never expected to see a quiet library this crowded on a Saturday morning.
- Upon discovering that the reclusive professor had finally published his masterpiece, I exclaimed, "Well, I'll be a monkey's uncle!"

## Origin

Uncertain; the term monkey’s uncle appears in 19th-century works and may allude to early ideas about what is now called the theory of evolution. The term may then have gained more currency after the widely publicized 1925 Scopes Trial in Tennessee, United States, in which a high-school teacher was found guilty of having violated a law prohibiting the teaching of human evolution in a state-funded school. (disputed)

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.