The 1959 United States Senate elections in Hawaii were held July 28, 1959. Following the admission of Hawaii as the 50th State in the union, the state held 2 simultaneous elections to determine its first senators.
The elections were split between the Republican and Democratic parties. The new senators took office on August 21. Oren E. Long was given seniority based on his service as Governor of Hawaii. Hiram Fong became the first Asian-American U.S. senator and the first Senator to be born outside of the contiguous United States.
| Election Name: | 1959 class 1 Senate election |
| Country: | Hawaii |
| Type: | presidential |
| Ongoing: | no |
| Next Election: | 1964 United States Senate election in Hawaii |
| Next Year: | 1964 |
| Image1: | Hiram Fong.jpg |
| Nominee1: | Hiram Fong |
| Party1: | Republican Party (US) |
| Popular Vote1: | 87,161 |
| Percentage1: | 52.89% |
| Nominee2: | Frank Fasi |
| Party2: | Democratic Party (US) |
| Popular Vote2: | 77,647 |
| Percentage2: | 47.11% |
| Map Size: | 300px |
| U.S. senator | |
| After Election: | Hiram Fong |
| After Party: | Republican Party (US) |
This election was for the class 1 term expiring in 1965. It was won by Republican Hiram Fong.
| Election Name: | 1959 class 3 Senate election |
| Country: | Hawaii |
| Type: | presidential |
| Ongoing: | no |
| Next Election: | 1962 United States Senate election in Hawaii |
| Next Year: | 1962 |
| Image1: | Oren E. Long (PP-75-4-020).jpg |
| Nominee1: | Oren Long |
| Party1: | Democratic Party (US) |
| Popular Vote1: | 83,700 |
| Percentage1: | 51.08% |
| Nominee2: | Wilfred Tsukiyama |
| Party2: | Republican Party (US) |
| Popular Vote2: | 79,123 |
| Percentage2: | 48.28% |
| Map Size: | 300px |
| U.S. senator | |
| After Election: | Oren Long |
| After Party: | Democratic Party (US) |
This election was for the Class 3 term expiring in 1963. It was won by Democrat Oren Long, who started an as-of-yet uninterrupted streak of Democratic victories in the Class 3 Senate seat in Hawaii. As of 2022, Tsukiyama's loss by a 2.8 point margin is the closest Republicans have come to winning this seat.
Following Long's victory, Governor William F. Quinn appointed Tsukiyama to the Hawaii Supreme Court.