People will soon be able to go to the Red Planet. But that very possibility opens a still more interesting - indeed truly grand - question: What will we create on Mars? It was to answer this question that the Mars Society sponsored its Mars City State Design Competition in early 2020. The challenge: Design a city state for 1 million people on Mars. The prizes: $10,000 and a grand trophy for the best design, with lesser prizes and trophies on down to Fifth. The designs had to take into account all aspects of the city: its technical basis, its economic foundation, its social and political system, and its architectural aesthetics. If a city is to succeed and grow, it will need to be a place that people will want to move to. How can we create such cities on Mars? The response to the challenge was fantastic, with 176 teams from all over the world entering the fray. All twenty of the semifinalist, finalist, and top five winning designs are presented in this volume. The "Foundation" team ranked 3rd of the 176.