Coldwave is a style of post-punk music that originated in Europe in the late 1970s and early 1980s and is known for its generally dark, gloomy (thus "cold") atmosphere and heavy reliance on synthesizers. It was popular predominantly in continental Europe (especially in France, Poland, and Belgium) and consisted largely of bands that were heavily influenced by British post-punk acts such as Joy Division and Siouxsie and The Banshees.
Whereas Polish coldwave bands such as Siekiera were more directly influenced by guitar-driven post-punk music, French and Belgian artists such as Clair Obscur and Siglo XX incorporated more synths and electronics and crossed over heavily with minimal wave and minimal synth. Due to the frequent genre-bending nature of these bands, it can be sometimes difficult to classify bands as strictly coldwave, post-punk, or minimal synth, but all of the artists in the coldwave scene shared a dark, cold, and metallic atmosphere and incorporated both guitars and synths.

By coincidence, the term was also used during the 1990s to describe bands from the US industrial rock underground, especially those signed to or affiliated with Reconstriction Records. Notable examples of this "American coldwave" are Chemlab, 16volt, and Acumen Nation.