Hugh P. Taylor Jr. and his (non-identical) twin brother lived in Arizona and New Mexico until 1943 when they moved with their parents to Los Angeles County, California.

In 1949 Hugh P. Taylor Jr. scored the highest on a state-wide chemistry exam and won a scholarship from the American Chemical Society, enabling him to attend California Institute of Technology (Caltech).

There he played varsity football, under head coach Bert LaBrucherie, and was inspired to study geology by a course taught by Professor Robert P. Sharp with the teaching assistants Clarence Allen and Leon Silver.

He spent the summers of 1955 and 1956 working for the U.S. Steel Corporation to explore for iron ores in southeastern Alaska.

[1] His 1959 Ph.D. thesis O¹⁸/0¹⁶ Ratios in Coexisting Minerals of Igneous and Metamorphic Rocks[4] was supervised by Samuel Epstein.

[3] He was a co-editor, with John W. Valley and James R. O'Neil, of the 1986 book Stable Isotopes in High Temperature Geological Processes[12] He did research with Bruno Turi on igneous rocks in Italy.

[13][14][15] Taylor and his colleagues did research on the interactions of the oceans with the underlying igneous crust, the hydrothermal circulation cells that form around intrusive igneous rocks, the geochemical origins of ore deposits[2] (such as the Comstock Lode),[16] and oxygen isotope analyses of minerals in stony meteorites.