We demonstrate the monolithic integration of an electro-thermal beam deflector based on a slow-light Bragg reflector waveguide with a VCSEL for the first time. The slow-light mode is laterally exited from a VCSEL and is directly coupled to the slow-light waveguide. The chip size is smaller than 300μm. The fabrication process is the same as that of conventional VCSELs. Continuous electro-thermal beam steering of over 9° with a diffraction-limited divergence angle of 2.2° is obtained. In addition, a potential in compact and high-resolution on-chip beam deflectors is suggested.