This course surveys algorithms that aid a group of biological or artificial agents in making collective decisions. The course specifically focuses on the area of computational social choice, which lies at the intersection of computer science and economics. This area has recently seen a growing number of real-world applications and this course reviews the theoretical foundations at the core of its success. The course will investigate issues which arise when a group of agents interact. This includes fairness, efficiency, preference elicitation, and strategic manipulations. These will be examined through frameworks of social choice theory (voting, fair division, matching, and facility location), mechanism design (auctions), and non-cooperative game theory (Nash equilibria, price of anarchy, and congestion games).