Guillermo Söhnlein (born May 18, 1966) is an Argentine-American businessman, best known as the co-founder of deep-sea exploration company OceanGate.

After relocating to the Northern Virginia region outside Washington, D.C., he worked with a number of technology startup ventures,[4][5][6] and advised several technology-related investment groups, incubators, and economic development agencies,[7][8] and gave frequent talks about the field.

[13] In 2010, the online community was transferred to the Space Frontier Foundation for ongoing growth, and IASE officially disbanded.

[21] In 2010, he re-launched the Ocean Exploration Committee of the Marine Technology Society, a nonprofit membership association supporting students and industry professionals in marine-related fields.

In 2011, Söhnlein founded the Sea-Space Initiative, a global project to provide collaboration in ocean and space industries.