One (disambiguation)

Look up one, I, or 1 in Wiktionary, the free dictionary.

One or 1 is the first natural number.

1, one, or ONE may also refer to:

• AD 1, first year of the AD era
• 1 BC, the year before AD 1
• One (pronoun), a pronoun in the English language
• Hydrogen, with an atomic number of 1
• The month of January, the first month of the year in the Julian and Gregorian calendars