This is an introductory course in Macroeconomics which I delivered to the first-year students at Cardiff Business School, Cardiff University, UK 2019/2020. The course is divided into 4 sections. The first section covers a brief overview of what macroeconomics is and key macroeconomic indicators. The second section focuses on the short run in which I cover the goods market and financial markets. In this section, the IS-LM model is covered in detail. Section three, the medium run, covers equilibrium in the labor market along with the AD-AS model. It also goes throng the natural rate of unemployment and the Phillips curve. Finally, section four on the long run covers economic growth and its determining factors.