Otto Hjersing Munthe-Kaas (31 August 1883 – 25 June 1981) was a Norwegian politician, businessman and military officer.
He was born in Fredrikshald as a son of Hugo Severin Munthe-Kaas and Ragna Hjersing and younger brother of Hugo Munthe-Kaas, and graduated as officer in 1904.
He was manager of Jøvik Sildolje- & Kraftforfabrik from 1914 to 1942.
He was a member of the municipal council of Tromsø from 1916 to 1923, and served as mayor of Tromsø from 1920 to 1921.
He was a deputy representative to the Storting from 1924 to 1927.