00
00, double zero or variants may refer to:

Arts and entertainment
 00 Agent, a fictional agent with a license to kill in the James Bond media
 Symphony No. 00 (Bruckner), an alternate name for Bruckner's Symphony in F minor
 "Double Zeros", an episode of Runaways
 Double Zero Records, a record label

Science and technology
 00 gauge, or OO gauge, a standard for model railways
 00, a common international call prefix
 00, an American wire gauge size
 00, a Very Fine grade of steel wool
 00, a shotgun ammunition size for buckshot

Other uses
 years such as 1900, 2000, 2100
 Size 00, a women's clothing size in the US catalog sizes system
 00, a pocket on some roulette wheels
 00, a grade of Italian flour

See also 
 Zero Zero (disambiguation)
 Double O (disambiguation)
 0 (disambiguation)
 00s (disambiguation)
 OO (disambiguation)
 0O (disambiguation)
 O0 (disambiguation)
 Leading zero
 Mobile Suit Gundam 00, an anime series