Is happy birthday capitalized?

Happy birthday is sometimes capitalized and sometimes not depending on the context. The capitalization rules for “happy birthday” and “birthday” are as follows:

  • Capitalize “Happy Birthday!” when it’s part of a greeting (e.g., “Happy Birthday, Lynn!”).
  • “Birthday” is not a proper noun like holidays such as Halloween or Thanksgiving, so the only other time it’s capitalized is when it begins a sentence or is part of a title (e.g., “Birthdays are special”).
  • Don’t capitalize “happy birthday” when “birthday” is a noun that functions as the subject of a sentence (e.g., “A happy birthday doesn’t always need to include cake and parties”).
  • Don’t capitalize “happy birthday” when it’s a direct object that receives the action in a sentence (e.g., “I hope you had a happy birthday yesterday”).
  • Don’t capitalize “happy” or “birthday” when either or both of these words are adjectives that modify another noun (e.g., “I spent the entire afternoon reading my happy birthday messages on Facebook” or “We ate the entire birthday cake”).

A QuillBot Grammar Check can help you proofread happy birthday messages for capitalization errors.