An embodiment of the disclosure provides a light source apparatus including a light-emitting module and a control unit. The light-emitting module is configured to provide a light. The control unit is configured to change proportion of a first sub-light and a second sub-light to form the light so that a circadian action factor (CAF) and a correlated color temperature (CCT) of the light varies along a CAF vs. CCT locus of the light different from a CAF vs. CCT locus of sunlight. A CAF vs. CCT coordinate of one of the first sub-light and the second sub-light is below the CAF vs. CCT locus of sunlight, and a CAF vs. CCT coordinate of the other one of the first sub-light and the second sub-light is above the CAF vs. CCT locus of sunlight. A display apparatus is also provided.