Born in Laredo, Texas, Peña earned a B.A. (1969) and a J.D. (1972) from the University of Texas at Austin and The University of Texas School of Law. Moving to Colorado, where he became an attorney, Peña was elected to the Colorado House of Representatives as a Democrat in 1979, where he became the Minority Leader. In 1983, Peña became the first Hispanic Mayor of Denver, and he was re-elected in 1987.