Halloween

Short answer: 'Halloween' is a proper noun and should be capitalized: 'Today is Halloween.'

Quick answer

'Halloween' should be capitalized. Use 'Today is Halloween.' rather than 'Today is halloween.'

Holiday names are treated like names → capitalize the first letter.
Lowercase on social posts is a stylistic choice, not standard grammar.
Compound modifiers: hyphenate before a noun (e.g., Halloween-themed party).

Core rule: holidays are proper nouns

Names of holidays are proper nouns and take an initial capital letter: Christmas, Easter, Thanksgiving, and Halloween. If you see 'halloween' in ordinary writing, change it to 'Halloween' unless a brand or stylistic choice intentionally lowercases it.

Correct: Today is Halloween.
Incorrect: Today is halloween.

Grammar specifics: possessives, plurals, and style

Possessives and plurals follow the usual rules but keep the capital: Halloween's decorations, Two Halloweens (rare). Lowercase forms belong to branding or deliberate tone, not standard writing.

Possessive: Halloween's traditions (not halloween's).
Plural: We had two Halloweens that year (only when you intentionally mean two celebrations).
Branding: A brand might use 'halloween'-don't copy that in formal writing.

Usage: Incorrect: halloween's traditions were explained. →
Correct: Halloween's traditions were explained.
Usage: Incorrect: we celebrated two halloweens last year. →
Correct: We celebrated two Halloweens last year.

Real usage by context: formal, school, and casual

Capitalize 'Halloween' in formal, academic, and professional contexts. In casual social posts, lowercase can be an aesthetic choice-but avoid it in anything shared or official.

When in doubt, capitalize - it's always acceptable.
Use lowercase only for intentional branding or personal stylistic posts.

Work: Please note the office will be closed on Halloween.
School: Halloween traditions vary by region and culture.
Casual: halloween vibes 🎃 (acceptable on personal social accounts, not in official posts)

Examples: copy-ready wrong/right pairs

Replace the incorrect line with the corrected one in one quick edit. Groups are arranged by context.

Work - Wrong: Company closed for halloween.
Work - Right: Company closed for Halloween.
Work - Wrong: Reminder: halloween office party on Friday.
Work - Right: Reminder: Halloween office party on Friday.
Work - Wrong: Added halloween meeting to your calendar.
Work - Right: Added Halloween meeting to your calendar.
School - Wrong: Our halloween assembly starts at 9.
School - Right: Our Halloween assembly starts at 9.
School - Wrong: Write an essay about halloween traditions.
School - Right: Write an essay about Halloween traditions.
School - Wrong: School newsletter: halloween costume winners.
School - Right: School newsletter: Halloween costume winners.
Casual - Wrong: Who's ready for halloween? 🎃
Casual - Right: Who's ready for Halloween? 🎃
Casual - Wrong: Going to a halloween concert tonight.
Casual - Right: Going to a Halloween concert tonight.
Casual - Wrong: Bought new halloween decorations.
Casual - Right: Bought new Halloween decorations.

Try your own sentence

Test the whole sentence, not just the word. Context usually makes the correct form obvious.

Fix your sentence: three quick rewrite templates

Pick a template, plug in details, and you'll have a correct sentence fast. Examples show originals and concise rewrites for tone.

Casual template: Capitalize and keep punctuation - 'Today is Halloween - can't wait!'
Formal/work template: Capitalize and add context - 'Today is Halloween. Please review the updated schedule.'
Headline/subject template: Be concise and title-case - 'Office Closed for Halloween' or 'Halloween Parade Today'

Rewrite:
Original: 'today is halloween, can't wait!' →
Casual: 'Today is Halloween - can't wait!'
Rewrite:
Original: 'today is halloween' →
Formal: 'Today is Halloween. Please note the office schedule will change.'
Rewrite: Original subject: 'today is halloween, office closed' → Subject: 'Office Closed for Halloween'

Hyphenation and spacing (compounds with Halloween)

When 'Halloween' modifies a noun before it, hyphenate the compound: Halloween-themed party. After the noun, the hyphen is usually optional: the party was Halloween themed. Always keep the capital.

Hyphen before a noun: Halloween-themed costume.
No hyphen after the noun: The costume was Halloween themed.
Always capitalize: Halloween-themed (not halloween-themed) unless branded otherwise.

Usage: Correct: Halloween-themed decorations.
Usage: Correct: The decorations were Halloween themed.

Similar mistakes to watch for

People often lowercase other holidays and day names. The same fix applies: capitalize the first letter and check hyphenation or possessives if needed.

Day names: Monday, Tuesday (not monday, tuesday).
Holiday names: Christmas, Easter, Thanksgiving.
Department or event names used as proper nouns: Homecoming, Graduation.

Wrong: merry christmas to all.
Right: Merry Christmas to all.
Wrong: we have an easter egg hunt next week.
Right: We have an Easter egg hunt next week.
Wrong: monday meeting moved to tuesday.
Right: Monday meeting moved to Tuesday.

Memory tricks and quick proofreading checks

Use simple checks while proofreading instead of memorizing every exception. These are fast and reliable for emails, posts, and headlines.

Swap trick: replace 'Halloween' with 'Christmas' - if you'd capitalize the replacement, capitalize the original.
Name trick: imagine the holiday as a person's name; if you'd capitalize it, capitalize the holiday.
Search trick: search your draft for common lowercase forms (halloween, christmas, monday) and fix any hits.

Usage: Test: 'Today is Christmas' → you'd capitalize, so 'Today is Halloween' needs a capital too.

FAQ

Is Halloween capitalized?

Yes. Halloween is a proper noun: 'Today is Halloween.'

Can I write 'halloween' in an informal social post?

You can as a stylistic choice, but it's nonstandard. Avoid lowercase in professional, school, or shared communications.

Should I hyphenate 'Halloween-themed'?

Yes when it precedes a noun: 'a Halloween-themed party.' After the noun, the hyphen is usually optional.

Does the possessive keep the capital (e.g., Halloween's)?

Yes. Use 'Halloween's' for possessives: 'Halloween's decorations' or 'Halloween's traditions.'

What's the fastest way to fix 'Today is halloween'?

Change the lowercase 'h' to uppercase: 'Today is Halloween.' Use your editor's find function to search for lowercase holiday names as a final check.

Quick tip before you send

Before sending an email or posting, do a quick search for common lowercase holiday and day names (halloween, christmas, monday) and fix any hits by capitalizing the first letter. For extra safety, run a grammar or style checker as your final pass.