Particles possessing two sides with different chemical properties are named Janus, as a reference to the double-faced god of Roman mythology. The combination of two different properties in the same system has been showing interesting for numerous applications. In this work, amphiphilic gold nanoparticles were synthesized by selectively coating the metallic nucleus hemispheres with two polymers, one hydrophobic and one hydrophilic. Then, a preferential growth of titanium dioxide over the hydrophilic face was performed. The results obtained by structural and physicochemical characterization confirmed the formation of gold nanoparticles with one hemisphere coated by titanium dioxide with low crystallinity and high porosity, proving the Janus character. The obtained Janus nanoparticles were tested as photocatalysts for hydrogen production from water. Results showed the superior activity in comparison to nanoparticles comprised only by titania. Thus, this study describes a new strategy to obtain Janus nanoparticles, which can be used for different applications and also demonstrates their importance in the fields of catalysis and production of hydrogen gas as renewable fuel.