Joseph Manuel Montoya (September 24, 1915 – June 5, 1978) was an American politician. A member of the Democratic Party who served as the lieutenant governor of New Mexico (1947–1951 and 1955–1957), in the U.S. House of Representatives (1957–1964) and as a U.S. Senator from New Mexico (1964–1977).
Born in Peña Blanca, New Mexico, he received his early education in public schools in Sandoval County and graduated from Bernalillo High School before continuing his education at Regis College in Denver, Colorado, where he earned a B.A. and Georgetown University's Law Center, where he earned an LL.B. In 1936 at age 21, while Montoya was still at Georgetown, he became the youngest representative in the history of the state to be elected to the New Mexico House of Representatives. In 1938, Montoya graduated from law school and was re-elected. The following year, he was elected the Democratic majority floor leader. Montoya was elected to the New Mexico Senate in 1940, once again becoming the youngest member of that body ever elected. By the time he left the Senate in 1946, Montoya had been twice reelected to the State Senate and held the positions of majority whip and chairman of the Judiciary Committee. From 1947 to 1957 he was elected Lieutenant Governor of New Mexico three times and also served two additional terms in the State Senate.
In 1957 Montoya was elected to the U.S. House of Representatives in a special election after the sudden death of the recently reelected New Mexico Congressman Antonio M. Fernández. In Congress Montoya gained a recognition as a political moderate, a dedicated Democrat, and a diligent legislator — qualities that earned him the esteem of his fellow legislators and made him an effective congressman. Montoya won the 1964 Senate election to complete the term of Dennis Chavez, who died in office. Thus began a twelve-year career in the Senate, where he served on the Appropriations Committee, the Public Works Committee, the Joint Committee on Atomic Energy, and Senate Watergate Committee. As a Senator, Montoya sought to link Hispanic-American issues with the broader civil rights movement in the 1960s and 1970s. Montoya initially supported the Vietnam War as fulfilling U.S. obligations to maintain regional security and preserve access to strategic natural resource; by 1971, Montoya was among the first voices calling for more immediate withdrawal increased inside and outside Congress until the final pullout of U.S. combat troops in 1973.
In 1976, with questions regarding his personal, political, and financial matters looming large in his bid for re-election, Montoya lost his Senate seat to former astronaut Harrison Schmitt. Montoya suffered from failing health throughout 1977. After traveling to Washington, D.C., in the spring of 1978 to seek medical care, Montoya died of liver and kidney failure there. He was interred at Rosario Cemetery in Peña Blanca, New Mexico.