If you've ever typed "favorite or favourite" into a search bar mid-sentence, you're not alone. Both spellings are correct English. Neither is a typo. The choice comes down entirely to which variety of English your audience reads, and that distinction matters more in professional writing than most people expect.
Where each spelling comes from
The word traces back through French ("favori") to the Italian "favorito." When English absorbed it, British writers kept the extra "u" as a nod to the French root. American English, shaped in part by Noah Webster's deliberate simplification campaign in the early 1800s, dropped the "u" and settled on "favorite." Webster did the same with colour/color, honour/honor, and behaviour/behavior.
So the split isn't random. It's historical. And it's held firm for over two centuries.
American English: favorite
Writers using American English spell it favorite. No "u." This applies to U.S. publications, American business documents, and any audience primarily based in the United States. The Associated Press Stylebook and Chicago Manual of Style both use the "favorite" spelling throughout.
If your company is headquartered in the U.S., your client base is American, or you're writing for an American publication, "favorite" is the correct choice. Using "favourite" in that context doesn't make your writing wrong, but it does make it look like it was written by someone who wasn't paying attention to the audience.
British, Australian, and Canadian English: favourite
Writers using British English, Australian English, or Canadian English spell it favourite. The "u" stays. This includes the United Kingdom, Australia, New Zealand, Ireland, South Africa, and most of Canada (Quebec French aside).
Canada is worth a brief note. Canadian English leans toward British spellings for words in this family, so "favourite" is the standard there, even though Canada sits right next to the U.S. and absorbs enormous amounts of American media. The Government of Canada writing guidelines consistently use the "favourite" spelling.
Why it matters in professional writing
Spelling consistency signals competence. A report that switches between "favorite" in one paragraph and "favourite" in the next suggests that no one proofread it. That's a small signal, but small signals add up.
The practical rule: pick the spelling your audience expects and hold it throughout every document. If you're writing to a mixed international audience and can't pick one, American English is the more neutral default in global business contexts, partly because so much international business communication runs through U.S. platforms and conventions. But if your client is based in London or Sydney, "favourite" is the right call.
This same logic applies to dozens of similar spelling pairs. The e-mail or email question, for example, follows a comparable pattern: usage has shifted over time, and the right answer depends on your style guide and context. Consistency within a single document is always more important than which variant you choose.
Quick reference: common words that follow the same pattern
The "our" vs "or" difference doesn't stop at favourite/favorite. The same split runs through a consistent set of words:
- colour (British) / color (American)
- honour (British) / honor (American)
- behaviour (British) / behavior (American)
- neighbour (British) / neighbor (American)
If you know which variant you're using for one of these, use the same variant for all of them. Mixing "colour" with "favorite" is exactly the kind of inconsistency that makes a document look unpolished.
What about spell checkers?
Most spell checkers flag the "wrong" variant as an error, but what counts as wrong depends entirely on the language setting. Microsoft Word set to "English (United Kingdom)" will underline "favorite" in red. Set to "English (United States)," it will underline "favourite." Neither is actually wrong; the software just defaults to one standard.
The fix is simple: set your word processor's language to match your audience, not your own location. Writers in the U.K. producing documents for American clients should switch the language setting before they draft, not after. Tools like Grammarly let you set a dialect preference (American, British, Australian, or Canadian English) so the tool flags the right variant automatically throughout your document.
One more thing: "favourite" as an adjective vs. a noun
Both spellings work as either a noun or an adjective, and the grammar is identical across dialects. "Favourite" (or "favorite") can be a noun: "This café is my favourite." It can also be an adjective: "my favourite restaurant." The spelling question is purely regional. The grammatical function doesn't change it.
Confusion about the word's role in a sentence is a separate issue from the spelling. If you're wrestling with how relative pronouns function around adjectives and nouns, the guide on "or which" vs "which" covers how to keep those constructions clean.
The short answer: use "favorite" for American audiences, "favourite" for everyone else. Set your spell checker accordingly, and check that you haven't mixed spellings before any document leaves your desk.