Nils Otto Myklestad (March 24, 1909 – September 23, 1972) was an American mechanical engineer and engineering professor. An authority on mechanical vibration, he was employed by a number of important US engineering firms and served on the faculty of several major engineering universities. Myklestad made significant contributions to both engineering practice and engineering education, publishing a number of widely influential technical journal papers and textbooks. He also was granted five US patents during his career.