Jordan was born in Houston, Texas's Fifth Ward. Jordan attended Wheatley High School and graduated magna cum laude from Texas Southern University in 1956 and from Boston University Law School in 1959. She passed the Bar Exams in Massachusetts and Texas before returning to Houston to open a law practice.

Active in the Kennedy-Johnson presidential campaign of 1960, Jordan wanted to be a part of the change. She unsuccessfully ran for the Texas House of Representatives in 1962 and 1964. Her persistence won her a seat in the Texas Senate in 1966, becoming the first African American state senator since 1883 and the first black woman to serve in that body. Reelected to a full term in the Texas Senate in 1968, she served until 1972.

In 1972, she was elected to the United States House of Representatives, becoming the first black woman from a Southern state to serve in the House. She received extensive support from President Lyndon Johnson, who helped her secure a position on the House Judiciary Committee.

After winning reelection, in 1974, she made an influential televised speech before the House Judiciary Committee supporting the impeachment of President Richard Nixon. Her legislative accomplishments include the renewal of the Voting Rights Act of 1965 and expansion of that act to cover language minorities. This extended protection to Hispanics in Texas which was opposed by Texas Governor Dolph Briscoe and Secretary of State Mark White. Her speech at the 1976 Democratic National Convention is considered by many historians to have been the best convention keynote speech in modern history. She sponsored the Community Reinvestment Act of 1977, legislation that required banks to lend and make services available to underserved poor and minority communities. Jordan retired from politics in 1979 and became a professor at the University of Texas at Austin Lyndon B. Johnson School of Public Affairs. She again was a keynote speaker at the Democratic National Convention in 1992. In 1995, Jordan chaired a congressional commission that advocated increased restriction of immigration and increased penalties on employers that violated US immigration regulations.

In 1973, Jordan began to suffer from multiple sclerosis. She began to have difficulty climbing stairs, started using a cane and eventually a wheelchair. She kept both her health and her lesbianism out of the press. Nancy Earl, her life partner for over twenty years, was her caregiver during her final illness and executor of her estate.

Jordan was awarded the Presidential Medal of Freedom in 1994. It was only one of many honors given her, including election into both the Texas and National Women's Hall of Fame. On January 19, 1996, Jordan lay in state at the LBJ Library on the campus of The University of Texas at Austin. She was buried in the Texas State Cemetery in Austin, and was the first black woman interred there.