Part of the Southern California Light and Space movement of the 1960s-70s, Orr was a contemporary conceptual artist dealing primarily with installation, sculpture, and painting. His work is based on a religio-philosophical conceptualization of space icons found in ancient religions and cultures, such as Egyptian symbolism and Buddhist spiritualism. In his installations, Orr worked with the elemental qualities of natural materials—stone, metal, water, and fire—with the intention of eliciting a visceral response from the viewer. Other materials Orr used include gold leaf, lead, blood, human skull, and AM/FM radio parts.  Orr's body of work also include monochromatic paintings, as well as large scale fountains that can be viewed in a variety of public and private spaces around the city of Los Angeles.

Orr is an internationally acknowledged artists with work in the collections of the Pompidou Center in Paris, France, Los Angeles County Museum of Art, the Whitney Museum and the Museum of Modern Art in New York City, The Farm in New Zealand, the San Francisco Museum of Art, and The Gugenheim.