Steven Weinberg (1933-2021) was a theoretical physicist and Nobel laureate who contributed tremendously to particle physics. Until his death, Weinberg was regarded by many as the greatest living scientist. His most well-known work was the formulation of electroweak theory for which he earned the 1979 Nobel Prize with Sheldon Glashow and Abdus Salam, but his research spanned many other fields. Examples include effective Lagrangians, quantum chromodynamics, supersymmetry, quantum gravity, and cosmology.