Liquid crystal elastomers (LCEs) are solid liquid crystals; they combine elasticity with orientational order. Mechanical strain therefore changes liquid crystalline order and the optical properties of these materials. Conversely, light can change the orientational order, and give rise to mechanical forces and changes in shape. Light–matter interactions in LCEs therefore involve a broad range of unusual phenomena, which raise a number of intriguing questions. There is great potential for device applications, but considerable challenges must first be overcome. The most appealing aspect of light–matter interactions in LCEs, however, is the promise of new physics waiting to be discovered.