Ø (disambiguation)
Ø (and ø) is a Scandinavian vowel letter.
The letter Ø or the symbol ∅ (a circle crossed by a diagonal slash) etc. may also refer to:
Language
- Close-mid front rounded vowel (IPA: ø)
 - Zero (linguistics) (∅)
 - Berber Academy yah (ⵁ), a Tifinagh letter, corresponding to "h"
 
Science, technology and engineering
- Slashed zero (
, 0︀), U+0030 U+FE00in Unicode, a representation of the digit 0 (zero) to distinguish it from the letter O - Slashed letter 'O' (O̸), a representation of the letter O to distinguish it from the digit 0 (zero)
 - The symbol for diameter (⌀), 
U+2300in Unicode - The symbol to represent a phenyl group
 - The symbol for the empty set ( or  as a character) in mathematical set theory, 
U+2205in Unicode 
Other uses
- Ø, Denmark, a piece of land in Jutland, Denmark
 - Half-diminished seventh chord (ø), in music
 - Ø, the solo identity of Finnish musician Mika Vainio of electronic music band Pan Sonic
 - Ø, the 2021 EP by British alt-rock band Blood Red Shoes
 
Similar symbols
Circle with a diagonal slash
- Circled division slash (⊘), 
U+2298in Unicode - No symbol, a similar symbol used to mark "no" or opposition to something
 
Circle crossed by a vertical bar
- Voiceless bilabial fricative (IPA: ɸ)
 - Phi (Φ and φ), a Greek letter, corresponding to "f" or "ph"
- Several uses of phi as a symbol for angles, etc.
 
 - Ef (Cyrillic) (Ф and ф), a Cyrillic letter, corresponding to "f" or "ph"
 
Circle with a vertical bar
- Yah (ⵀ), a Tifinagh letter, corresponding to "h" or "b"
 
Circle with a horizontal bar
- Voiceless dental fricative (IPA: θ)
 - Theta (Θ and θ), a Greek letter, corresponding to "th"
 - Theta nigrum (ꝋ) for "obiit" ="died"
 - Fita (Ѳ and ѳ), an Old Cyrillic letter, corresponding to "f" and transliterating Greek theta
 - Oe (Cyrillic) (Ө and ө), Cyrillic barred O, representing an open-mid front rounded vowel in some Turkic and Mongolic languages
 - Yab (ⴱ), a Tifinagh letter, corresponding to "b"
 - Load line mark (⦵), showing the maximum draft of a ship
 - Standard state (⦵), in chemistry