This course is an overview introduction to the physics of the fourth state of matter, known as plasma. Plasma physics is the study of ionized gas, which is the state of matter for 99.9% of the known universe, from astrophysical plasmas to the solar wind and radiation belts to the Earth's ionosphere. Plasma phenomena are also important for thermonuclear fusion-driven energy generation. Topics to be covered during the course include the motion of charged particles in electric and magnetic fields, dynamics of fully ionized plasmas from microscopic and macroscopic viewpoints, magneto-hydrodynamics, plasma radiation, electric discharges, applications to fusion devices, ionospheric and space physics, etc.