Lewis Buckley Stillwell (March 12, 1863 – January 19, 1941) was an American electrical engineer and the president of American Institute of Electrical Engineers (AIEE) from 1909 to 1910.

He received the AIEE Lamme Medal (1933)[3] and the AIEE Edison Medal (1935), for "his distinguished engineering achievements and his pioneer work in the generation, distribution, and utilization of electric energy.

"[4][5] He also was inducted into the IEEE's Electrical Engineering Hall of Fame.

His papers (1886-1939) are held in the Manuscript Division of the Princeton University Library.

[9][10][11] "He is credited with a number of inventions including the Stillwell regulator and a time-limit circuit breaker.