A self-righting toothbrush includes a shaft having a head section, a medial section and a tail section. The medial section has curved pivot surface configured to contact a horizontal support surface at a pivot point, the pivot surface allowing the toothbrush to roll on the support surface. An external ballast has an outer contour exposed at a surface of the shaft. The ballast is positioned to induce the toothbrush to roll on the support surface from an unstable orientation wherein the bristles are non-vertical, to a stable orientation wherein the bristles are vertical (up or down). In one aspect, the ballast has an irregular outer contour. In another aspect, the ballast outer contour is limited to the toothbrush medial section. In another aspect, the ballast outer contour provides a relatively flat reference protrusion of the pivot surface that is opposite from a relatively tall primary protrusion of the pivot surface.