Kathleen Harrison is an American ethnobotanist, artist, and educator known for her work preserving ancestral knowledge about medicinal and ritual plants. Since the 1970s, she has carried out extensive fieldwork with Indigenous Peoples of Mesoamerica, the Amazon, the Pacific, and various West Coast subcultures, studying the traditional use of sacred plants and fungi and the cosmologies that sustain them.

She is the co-founder and president of Botanical Dimensions, a nonprofit organization she created in 1985 with her then-husband, Terence McKenna. Through this foundation, she has spent more than thirty years conserving medicinal and shamanic species and documenting the traditional knowledge associated with them.

As an independent scholar, Harrison integrates science, art, and spirituality to explore how different cultures understand and express their relationship with nature through stories, rituals, and healing practices. A published author and photographer, she teaches ethnobotany workshops in Northern California, intensive field courses in Hawai‘i, and lectures internationally.

Her teaching seeks to cultivate a deep understanding of the natural world, the role of plants and fungi in human history, and our responsibility as guardians of biological and cultural diversity. She currently divides her time between rural Northern California and Hawai‘i’s Big Island.