TH1 may refer to: Th1 cell, a type of T helper cells Tianhe-I (TH-1), a Chinese super computer TH1 the scripting language for web pages in fossil (software), the Fossil SCM Windows 10 Threshold 1 TH-1, a character in The Source (Ayreon album) TH-1 (Phytophthora infestans), a subpopulation of the Ia mtDNA haplotype of the A2 mating type th1 [evnslower], a track by Aphex Twin