Atrium

Atrium may refer to:

== Music == "ATRIUM", a 2025 track by Toby Fox from Deltarune Chapters 3+4 OST from the video game Deltarune == Anatomy == Atrium (heart), an anatomical structure of the heart Atrium, the genital structure next to the genital aperture in the reproductive system of gastropods Atrium of the ventricular system of the brain Pulmonary alveolus (also known as atrium alveolus), microscopic air sac in the lungs