Warner was born in 1954 in Indianapolis, Indiana, and raised in Alexandria, Virginia. He attended George Washington University, where he earned a bachelor's degree in law and economics in 1977. After graduating, he worked as a corporate lawyer and business executive.
Warner entered politics in 1986 when he was elected to the Virginia State Senate, where he served until 1991. In 1991, he was elected to the United States Senate, where he served for two terms. During his time in the Senate, he focused on issues such as healthcare, education, and the environment.
Warner left the Senate in 2001 and became the Chairman and CEO of Nextel Communications, a wireless telephone company. In 2002, he was elected Governor of Virginia, serving until 2006. As governor, he focused on improving education, promoting economic development, and reducing crime.
After leaving office, Warner taught at the University of Virginia and worked as an investment banker. He was elected to the United States Senate again in 2008, and he has served there since then. In the Senate, he has continued to focus on issues such as healthcare, education, and the environment.
Warner is a member of the Democratic Party. He is married to Lisa Collis, and they have three children.