millionaire

American  

[mil-yuh-nair] / ˌmɪl yəˈnɛər /

Or millionnaire

noun

1. a person whose wealth amounts to a million or more in some unit of currency, as dollars.

2. any very rich person.

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millionaire British  

/ ˌmɪljəˈnɛə /

noun

1. a person whose assets are worth at least a million of the standard monetary units of his country

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Other Word Forms

• millionairedom noun
• millionairess noun
• nonmillionaire noun

Etymology

Origin of millionaire

1820–30; < French millionnaire, equivalent to million million + -aire -ary

Compare meaning

How does millionaire compare to similar and commonly confused words? Explore the most common comparisons:

• multimillionaire vs. millionaire

Explanation

A millionaire is someone who has at least a million dollars. If you're a millionaire, you are incredibly wealthy — but not as rich as a billionaire. In U.S., if you have a million dollars — or things that are worth that much, like a million-dollar house — you're a millionaire. In the U.K., a millionaire has a million pounds. This word describes a specific amount of wealth, but it's also a metaphor for "rich," so you might say, "My neighbors are millionaires — they travel to foreign countries all the time!" The first American millionaire was John Jacob Astor, who earned his riches from 18th-century fur trading.

Example Sentences

The millionaire class has been on a steady climb in Maine in recent years, as it has in many other states, alongside the postpandemic stock market boom.

From The Wall Street Journal • Apr. 19, 2026

Do you have to be a millionaire to become an F1 driver?

From BBC • Apr. 17, 2026

Though the businessman and Mormon missionary never mined for gold himself, he became California’s first millionaire by monopolizing the sale of supplies to those who did.

From The Wall Street Journal • Apr. 16, 2026

Are there many of them on the market, and do you need the bank balance of a celebrity millionaire?

From BBC • Mar. 28, 2026

And these are the granddaughters of the distinguished millionaire.

From "The Diary of a Young Girl" by Anne Frank