This lecture investigates various areas of financial behaviour and its psychological basis. Emotions and social concerns can play an important role in financial decisions. Influences on decision behaviour, like nudging, herding, and other biases are systematically investigated in regard with financial literacy. Private as well as professional spending, saving, and investment decisions are often better described by bounded rationality and various choice heuristics. Normative theory is further challenged by player heterogeneity and variations in the individual decision processes. The course builds on microeconomic theory and reaches from behavioural game theory to experimental economics with its main focus on the financial domain.