Yarborough was born in Chandler, Texas as the seventh of nine children. He was appointed to West Point in 1919 but dropped out and became a teacher. Yarborough took classes at Sam Houston State Teachers College and worked his way into the University of Texas. He graduated from the University of Texas Law School in 1927 and practiced law in El Paso, Texas until he was hired as an assistant Texas attorney general in 1931. Governor James Allred appointed Yarborough district judge in Austin, and Yarborough was elected to that office that same year in 1936. Yarborough's first run for state office was coming in third in the Democratic primary for state attorney general in 1938. He served in World War II after 1943, ending service as a Lt. Colonel.
Historically, Texas has been a one party state of the Democratic Party. Democrats would win every statewide office, a majority of the congressional delegation, and large majorities in the state legislature. Thus, general elections were formalities, and the real battles took place in the Democratic party primaries. The Democratic primaries would be heated battles between the conservative wing (pre-presidency LBJ, Gov. Shivers, John Connally) and the liberal wing (Yarborough) that identified more with the national party.
Ralph Yarborough then ran in the primaries for governor in 1952 and 1954 against conservative Allan Shivers, drawing support from labor unions and liberals. Yarborough denounced the corrupt "Shivercrats" for veterans' fraud in the General Land Office and for endorsing the Republican Eisenhower/Nixon ticket for President instead of Democrat Adlai Stevenson in 1952. Shivers portrayed Yarborough as an integrationist supported by communist labor unions. Yarborough then lost another gubernatorial race in a close primary runoff in 1956 to U.S. Sen. Price Daniel. When the Daniel resigned from the Senate in 1957 to become governor, Yarborough ran in the special election to fill the empty seat needing only a plurality of votes (no runoff needed) to win. He won the special election with 38% of the vote to join fellow Texan Lyndon Johnson in the Senate. Ralph Yarborough was a very different kind of Southern senator. He refused to sign the Southern Manifesto opposing integration and supported national Democratic goals of more funding for healthcare, education, and environment. Himself a veteran, he worked to expand the GI Bill of Rights to cold war veterans.
In 1958, Ralph Yarborough easily defeated conservative William A. Blakley in the Democratic primary and cruised onto victory in the general election against Republican Roy Whittenburg. Ralph Yarborough sat in the Dallas, Texas motorcade where John F. Kennedy was assassinated in 1963, in the car behind the president and Gov. John Connally.
In 1964, Yarborough again won the primary without a runoff and went on to general election victory with 56.2% in LBJ's 1964 Democratic landslide, this time defeating future president George H.W. Bush who attacked Yarborough for his vote for the Civil Rights Act. Although Yarborough supported Johnson's domestic agenda, he was critical of his foreign policy and the Vietnam War. In 1969, Sen. Yarborough became chairman of the Senate Committee on Labor and Public Welfare.
In 1970, businessman and former congressman Lloyd Bentsen, Jr. won an upset victory against Yarborough in the Democratic primary. Bentsen went on to win the general election against George H.W. Bush.
In 1972, Ralph Yarborough made a comeback effort to win the Democratic nomination for U.S. Senator to challenge Republican Sen. John Tower. Yarborough won the first round of the primary but lost in the primary runoff to Barefoot Sanders. This was to be Ralph Yarborough's last run for office.
He died in 1996 in Austin, Texas and was buried in the Texas State Cemetery (the Arlington of Texas). Ralph Yarborough left a legacy in the modernization of the state of Texas and achieved political power at a peak of Texas's national power during the Johnson years. In a state famous for closeness between business interests and politicians (LBJ, George W. Bush), Yarborough was combative with the dominant industries of oil and gas, always pushing for petroleum's fair share of the public burden.
Yarborough also was one of the last of the New Deal Democrats and liberals in a conservative southern state. The window of opportunity for a liberal in Texas to reach such a high office was narrow, between the Great Depression and the Great Society. Yarborough represented this brief political moment, both preceded and followed by conservatives (Phil Gramm) and reactionaries ("Pappy" O'Daniel). Ralph Yarborough is remembered as the acknowledged "patron saint of Texas liberals."
The University of Texas at Austin Press published a biography titled, Ralph W. Yarborough: The People's Senator, by Patrick L. Cox. It features a forward written by Sen. Edward Kennedy (D-MA).