• Direct observation of one-dimensional charged domain walls (CDWs) in ferroelectric ZrO2, representing an extreme limit of domain-wall confinement.
• Both head-to-head and tail-to-tail CDWs exist as atomic-scale line defects, not extended 2D interfaces.
• Stabilization of 1D CDWs via a self-balancing oxygen compensation mechanism that mitigates electrostatic energy.
• Discovery introduces a new class of polar topological objects with potential for domain-wall nanoelectronics and reconfigurable functionality.