Carl Albert Magnus Hallenborg (26 March 1894 – 22 December 1980) was a Swedish diplomat. Hallenborg joined the Swedish Foreign Service in 1921. He held diplomatic positions in Vienna, Chicago, Antwerp, and Rotterdam, becoming vice consul in Minneapolis in 1931 and first legation secretary in Helsinki in 1934. Hallenborg served as Consul General in Bombay between 1944 and 1948, in Antwerp between 1948 and 1949, and in London from 1949 to 1960.