Hatsune Miku (初音ミク), sometimes referred to as Miku Hatsune, is a humanoid persona voiced by a singing synthesizer application developed by Crypton Future Media, headquartered in Sapporo city. She uses Yamaha Corporation's Vocaloid 2 and Vocaloid 3 singing synthesizing technologies. She also uses Crypton Future Media's Piapro Studio, a singing synthesizer VSTi Plugin. She was the second Vocaloid sold using the Vocaloid 2 engine, and the first Japanese Vocaloid to use the Japanese version of the Vocaloid 2 engine. Her voice is sampled from Japanese voice actress Saki Fujita. Hatsune Miku has performed at her concerts onstage as an animated projection. Hatsune Miku is portrayed to be a 16-year-old girl with long turquoise pigtails.

The name of the character comes from merging the Japanese words for first (初, hatsu), sound (音, ne) and future (Miku (ミク) sounds like a nanori reading of future, 未来, normally read as "mirai"), referring to her position as the first of Crypton's "Character Vocal Series". According to Crypton, her name is meant to signify the "first sound from the future".