Kazumichi Fujii (born 1981) is a Japanese soil scientist and Senior Research Scientist at the Forestry and Forest Products Research Institute. His research focuses on soil formation, forest ecosystems, and environmental change, with fieldwork spanning Japan and tropical regions. He is also known for making soil science accessible to general readers. His best-known book, "Soil: The Last Great Mystery of the Earth," explores how soils are formed, why they differ across environments, and how they sustain food production and life on Earth.