In situ building materials and energy resources are necessary for the long-term human habitation of Mars. Olivine ((Mg,Fe)2SiO4) is a regionally abundant mineral on Mars and may potentially serve both purposes. Here we assess olivine hydrolysis (i.e., serpentinization) and related products including magnesite (MgCO3) as a means to produce a Mg-based cement and molecular hydrogen (H2) as an energy resource. Magnesium oxide (MgO) may be derived from Mg(OH)2 dehydration or calcination (i.e., thermal decomposition) of MgCO3. In laboratory experiments, Mg-based concrete using MgO achieved a compressive strength in excess of 20 MPa. Serpentinization-related H2 gas concentrations increased with increasing temperature (20 to 50 °C) and decreasing olivine particle size reaching a maximum H2 production rate of 4.73 μmol g 1 day 1 , 3 orders of magnitude greater than previously observed. Results from this study indicate that serpentinization and related products serve as a viable pathway for both concrete and fuel production on Mars with minimal energy expenditure and primarily constrained to the availability of water. Moreover, this process would work equally as well on Earth and has significant potential to decrease global industrial CO2 emissions.