Bo Yngve Thidé (born 8 January 1948) is a Swedish physicist and professor emeritus at Uppsala University. He has studied radio waves and other electromagnetic radiation in space, particularly their interaction with matter and fields. In the mid-1980s, Thidé published a series of papers together with Bengt Lundborg on a highly accurate analytic approximation method to calculate the full three-dimensional wave pattern, spin angular momentum (polarization) and other properties of radio waves propagating in an inhomogeneous, magnetized, collisional plasma.