We present results of a study of tunnel junction aging in which the early time dynamics are captured by in situ room-temperature monitoring of electrical properties of Al-AlO x -Al planar tunnel junctions beginning when the deposition of the counterelectrode is complete. The observed stretched exponential dependences of the conductance and the capacitance, which are established over a dynamic range in frequency of 10 9 , manifest off-equilibrium dynamics imposed by annealing and correlated relaxations of interface traps. Bias voltage is used as a control parameter to create bias-dependent aging trajectories that exhibit memory and age-dependent relaxations that are typical for glasses. Simple tunnel barrier modeling using circuit parameters that depend only on the interface provide a comprehensive understanding of this unexpected glassy behavior.