Ball was elected to the Senate in the 1942 election, receiving 47% of the vote against Farmer-Labor, Independent and Democratic opposition. Because Ball's 1940 appointment had been set to expire on the day of the next senatorial election rather than the expiration of Lundeen's term, Ball ceased being senator on the day that he won a six-year term. Ball then took office again, as a freshman senator on January 3, 1943, and served until January 3, 1949. In 1943, he was one of four Senate sponsors of the bill to establish what would become the United Nations.