Thermodynamics is based on a coarse-grained approach, from which its fundamental variables emerge, effectively erasing the complicate details of the microscopic dynamics within a macroscopic system. The strength of Thermodynamics lies in the universality provided by this paradigm. In contrast, quantum mechanics focuses on describing the dynamics of microscopic systems, aiming to make predictions about experiments we perform, a goal shared by all fundamental physical theories, which are often framed as gauge theories in modern physics. Here we introduce a gauge theory approach for quantum thermodynamics, defining gauge invariant work, heat, entropy and their connections to quantum phenomena. This provides a complete framework for quantum thermodynamics grounded in the principle of gauge invariance.