English UsageComparison guide
Odour vs. Odor
“Odour” and “odor” are regional spellings of the same noun. “Odour” is standard in UK English, while “odor” is the standard US spelling.
Use “odour” for UK English and “odor” for US English.
Key details
Confusion Familyregional spelling variant
Rule FamilyBritish and American spelling
Termsodour, odor
Variant ScopeOdour is the UK spelling and odor is the US spelling of the same noun.
Further guidance
Core difference
The meaning is the same; the distinction is spelling convention.
Fast Test
Use “odour” in UK-oriented spelling and “odor” in US-oriented spelling, then stay consistent with the document’s regional style.
Usage Boundary
Do not present one form as universally correct and the other as an error; both are standard in their respective regional conventions.
Sources and evidence
Sources are shown with the role they play in this guide. Historical or style-sensitive claims are kept within the evidence boundary described above.
- odour — Cambridge Dictionary (opens in a new tab)Cambridge University Press · Direct evidence for odour as the UK spelling in the smell sense.
- odor — Cambridge Dictionary (opens in a new tab)Cambridge University Press · Direct evidence for odor as the US spelling of odour.