A mobile carrier includes a first frame, a directional wheel pivoted to the first frame, a second frame pivoted to the first frame, a steering adjustment mechanism connected to the second frame, and a steering wheel. The steering adjustment mechanism includes a first rotating element and a second rotating element coupled to the first rotating element. When a first rotating axis of the first rotating element is perpendicular to a plane, the first and the second rotating elements are locked to each other and are capable of rotating around the first rotating axis simultaneously. When a second rotating axis of the second rotating element is perpendicular to the plane, rotational degree of freedom of the first rotating element is restricted, and the second rotating element is capable of rotating around the second rotating axis relative to the first rotating element. A steering adjustment mechanism is also provided.