William Sanford Nye —a.k.a. Bill Nye the Science Guy— (born November 27, 1955, Washington, D.C.), is a science educator and comedian who began his career as an engineer at Boeing. He is best known as the host of the Disney/PBS children's science show Bill Nye the Science Guy (1993–98) and for his many subsequent appearances in popular media as a science presenter. When portraying "The Science Guy", he wears a light blue lab coat and a bow tie, and takes on the persona of an excited, jocular science educator. Nye is a graduate of Cornell University with a Bachelors of Science degree in Mechanical Engineering. Among other things, he developed a hydraulic pressure resonance suppressor still used in the 747 and fitted the Mars rovers with photometric calibration Mars Dials.
Professor Proton contacts Leonard to ask to read a paper he wrote. Sheldon, who has loved Professor Proton since childhood, seeks revenge by deceiving Bill Nye to get him to Caltech.  In the end, Sheldon has a new person who takes out a restraining order against him.He will reappear in "The Conjugal Configuration".
- His counterpart, Professor Proton, is also a graduate of Cornell University.
- Carl Sagan was one of Bill Nye's professors at Cornell. Sheldon has a restraining order from Sagan. ("The Vacation Solution")
- Sheldon would later receive a restraining order from Nye himself ("The Proton Displacement").
- He appeared alongside Neil deGrasse Tyson in an episode of Stargate Atlantis. Dr. Tyson made a cameo in "The Apology Insufficiency", while Sheldon referenced "Stargate" in "The Cushion Saturation".
- Penny knows him as "Creepy Old Guy from Dancing with the Stars".
- Bill Nye is acquainted with Buzz Aldrin, who had a cameo in "The Holographic Excitation".