A high power microscopy illumination system is disclosed, having a liquid cooled, Solid State Light Source (SSLS) unit including one or more LED light sources, thermally mounted on a cold plate, which is cooled by a closed-loop liquid cooling system including a remote unit housing a heat exchanger. The SSLS unit with the LED light source is compact and lightweight, and is mechanically and optically directly coupled to the illumination port of the microscope, for efficient optical coupling to the imaging plane. High capacity cooling of the LEDs, enables the LEDs to be driven at higher current densities for increased optical output and for operation with improved thermal stability. The LED driver circuitry may also be housed within the SSLS unit and liquid cooled. The SSLS unit is vibrationally isolated from vibration-causing components of the cooling system, such as cooling fans and other bulky components, which are housed in the remote unit.