Hydro Flask is a water bottle brand owned by American conglomerate Helen of Troy Limited. The brand became popular during mid-to-late 2019 and early 2020. Hydro Flask is particularly well known among Millennials and Gen Z, as well as college students and the "VSCO girl" subculture; social influencers and celebrities, especially on TikTok, increased the brand's popularity. Hydro Flask's prominence has played a role in the rising environmental and health consciousness of millennials and zoomers and has influenced the quality and appearance of other reusable water bottles.