R. Buckminster Fuller's design and architectural work is frequently described as being "inspired by nature." However, to date there has been little investigation of this claim. What was Fuller's understanding of "nature" and how did it affect the conception, production, and presentation of his work? This thesis attempts to characterize R. Buckminster Fuller's understanding of nature, which will be called a model of nature, and to trace its impact upon his work over the course of his career using an interdisciplinary historical approach. Fuller's model of nature was a unique amalgam of religious, scientific, and philosophical ideas from the past and the present. It drew upon Enlightenment ideas about natural laws, and American Transcendentalist ideas about the spiritual importance of experiences in the natural world. Fuller combined these with 20th century ideas about technological progress and the efficiencies of mass production. This model of nature affected both the conception and presentation of Fuller's work. For example, his understanding of nature shaped the design of the 4D/Dymaxion house from the late 1920s until the 1940s, in particular the notion of the house as a living organism and the use of natural metaphors such as circulation and respiration to describe its functions. Other works are also discussed. Fuller's understanding of nature was present throughout his lifetime, yet it did not always figure into the presentation of his work. Fuller deftly adapted his message to his audiences—in some cases foregrounding the role of nature in his work, in other cases omitting it altogether. He found a particularly avid audience for nature-related narratives of his work with the 1960s counterculture, and established common ground with the counterculture in part by appealing to their ideals of pastoralism, holism, and individualism. The countercultural understanding of Fuller as a designer deeply inspired by nature has persisted to this day. The 1960s also saw the rise of alternative models of nature, such as an eco-political model of nature adopted by the burgeoning environmental movement; and a cybernetic ecology model of nature that grew out of systems theory and cybernetics. In the thesis, these two alternate models of nature are compared and contrasted with Fuller's. In particular, comparison with the eco-political model of nature affords the opportunity to discuss whether Fuller was an early environmentalist, as some scholars have argued, or whether, as I argue, he largely chose to sidestep the environmental debate. Taken together, these investigations into Fuller's model of nature help us to understand his unique, comprehensive view in which nature, mankind and technology were bound together in continuous coevolution under the benevolent watch of a Greater Intellect. Nature was a source that he returned to again and again to provide conceptual and formal inspiration for his architectural projects; confirmation of his religious faith; and a way of understanding the role of technology in human civilization.