Vincent Ellis McKelvey, American geologist and author (d. 1987)
Vincent Ellis McKelvey (April 6, 1916 – January 23, 1987) was an American geologist and earth scientist. Recognized as an international authority on deep-sea mineral deposits, he spent 46 years with the United States Geological Survey. From 1968 to 1982, he served as scientific adviser and senior deputy to the United States delegation to the Law of the Sea Conference of the United Nations, where fellow delegates often depended on his ability to render complex scientific issues into plain English.

He joined the US Geological Survey, a branch of the Department of the Interior, in 1941. He was placed in charge of its explorations for uranium after World War II, was assistant chief geologist for economic and foreign geology by 1962 and was named senior research geologist three years later. McKelvey was named chief geologist of the Geological Survey in 1971 shortly before he became its ninth director, a post he held through 1977.

The McKelvey diagram (or box), a visual representation of how to classify a particular mineral resource based on the value of its production (economic, marginal, etc.) and the geologic certainty of its presence (measured, inferred, hypothetical, etc.), is named after him.