Leopold Benno Felsen (May 7, 1924 – September 24, 2005) was a German-born American electrical engineer and physicist known for his fundamental contributions to electromagnetism and wave-based disciplines.

While his parents survived and joined him in the United States in 1946, many of his family members including her elder sister Johanna died during the Holocaust.

[3][4] He received his bachelor, master, and PhD degrees from the Polytechnic Institute of Brooklyn, in 1948, 1950, and 1952, respectively, all in electrical engineering.

[2] In 1973, he coauthored with Nathan Marcuvitz a textbook titled Radiation and Scattering of Waves which published by Prentice Hall in its Electrical Engineering Series.

This was a classic worldwide textbook which immediately became widely used by researchers[6] and has been described as "The Bible" in applied electromagnetism.