William Jason Morgan (October 10, 1935 – July 31, 2023) was an American geophysicist who made seminal contributions to the theory of plate tectonics and geodynamics.

His father William owned a hardware and dry goods store and his mother Maxie Ponita (Donehoo) Morgan was a French teacher and volunteered with the Girl Scouts of America.

[5] His first major contribution, made in the late 1960s, was to relate the magnetic anomalies of alternating polarity, which occur on the ocean bottom at both sides of a mid-ocean ridge, to seafloor spreading and plate tectonics.

From 1971 on he worked on the further development of the plume theory of Tuzo Wilson, which postulates the existence of roughly cylindrical convective upwellings in the Earth's mantle as an explanation of hotspots.

[6] "Essentially all of the research in solid-earth geophysical sciences in the past 30 to 35 years has been firmly grounded upon Jason Morgan's plate tectonic theory," Dahlen said.