The surface characteristics, such as topography, roughness, and hardness, of orthodontic archwires are important determinants of the effectiveness of archwire-guided tooth movement. They also affect the corrosion potential and the aesthetics of orthodontic components. This study uses a surface profilometer and a hardness tester to evaluate the surface roughness and hardness of four commonly used types of orthodontic archwire: (1) stainless steel (SS) wire, (2) conventional nickel-titanium (NiTi) alloy wire, (3) improved superelastic NiTi-alloy wire (also called low-hysteresis (LH) wire), and (4) titanium molybdenum alloy (TMA) wire. In addition, the surface topography of the four types of archwire is obtained using scanning electron microscopy (SEM). SEM results show that the surface topography of the four types of archwire varies. LH wire and NiTi wire have similar surface topographies, which differ from those of SS wire and TMA wire. SS wire has the smoothest surface (roughness of 0.051 ± 0.023 μm, mean ± SD), followed by TMA wire (0.206 ± 0.007 μm), NiTi wire (0.627 ± 0.072 μm), and LH wire (0.724 ± 0.117 μm). In addition, SS wire has the hardest surface (hardness of 405.4 ± 9.9 kg/mm2), followed by TMA wire (303.3 ± 13.2 kg/mm2), LH wire (215.1 ± 48.5 kg/mm2), and NiTi wire (195.4 ± 17.2 kg/mm2). NiTi wire and LH wire have similar surface topographies, surface roughnesses, and hardnesses. It might therefore be unnecessary for orthodontists to substitute NiTi wires with LH wires.