Ø (disambiguation)

For the Underoath album, see Ø (Disambiguation).

The letter Ø and the similar-looking symbol ∅ may refer to:

Language

⟨Ø⟩ and ⟨ø⟩, a Scandinavian vowel letter
⟨ø⟩, the IPA letter for a close-mid front rounded vowel
⟨ɸ⟩, the IPA letter for an unvoiced bilabial fricative
⟨θ⟩, the IPA letter for an unvoiced dental fricative
⟨∅⟩, the symbol for zero in linguistics
⟨Ф⟩ and ⟨ф⟩, the Cyrillic letter ef, corresponding to "f" or "ph"
⟨Φ⟩ and ⟨φ⟩, the Greek letter phi, corresponding to "f" or "ph"
⟨Θ⟩ and ⟨θ⟩, the Greek letter theta, corresponding to "th"
⟨Ѳ⟩ and ⟨ѳ⟩, the Old Cyrillic letter fita, corresponding to "f" and transliterating Greek theta
⟨Ө⟩ and ⟨ө⟩, Cyrillic barred O, representing an open-mid front rounded vowel in some Turkic and Mongolic languages
⟨中⟩, Chinese logogram meaning "middle" in several languages, and a component of some names of China in Chinese

Ø is the solo identity of Finnish musician Mika Vainio of electronic music band Pan Sonic
Ø, Denmark, piece of land in Denmark meaning island
0̸ or Slashed zero, a representation of the number 0 (zero) to distinguish it from the letter O
Empty set ( $\varnothing$ ) in mathematical set theory
Diameter, by the symbol ⌀
Half-diminished seventh chord, in music by the symbol ^ø
Plimsoll line (o), the line where the hull of a ship meets the surface of the water
Standard state (o), in chemistry
In German-speaking countries, Ø is also used as a symbol for average value: average in German is Durchschnitt, directly translated as cut-through.