An indirect LED light fixture for illuminating tennis courts and other indoor facilities is disclosed. The light fixture is highly efficient and provides for even distribution of light. The fixture employs at least one LED (Light Emitting Diode) light source equipped with at least one optical lens having a predefined light output beam pattern. Light emitted by the LED is controlled and directed to a ceiling or a wall by a lens to achieve highly uniform illumination of the surface area desired to be illuminated. The beam angle of the light emitted by the LED light source may be adjustable by adjustment of the position of the lens in relation to the light emitting side of the LED light source. The light fixture has minimal reflection losses, a wide adjustment range of light output, and a high color rendering index.