204 was a year of the Julian calendar, in the third century AD.

204 may also refer to: 204 BC, year of the pre-Julian Roman calendar, in the third century BC 204 (number) Peugeot 204, a small family car

See also AS-204 (disambiguation) VA-204 (disambiguation) USS Nirvana II (SP-204), a United States Navy patrol vessel in commission from 1917 to 1918 204 Kallisto 204 (North Irish) Field Hospital M204 (disambiguation) No. 204 Squadron RAF Flight 204 (disambiguation) List of highways numbered 204