August William "Bill" Ritter, Jr. (born September 6, 1956) is an American politician of the Democratic Party, and the current Governor of the state of Colorado. Before his election in 2006, he served as the district attorney for Denver. He is the first native-born governor of Colorado since 1975, as well as being the first Democratic governor to serve with a Democratic majority in the Colorado General Assembly in 50 years.

Ritter was born in Denver and raised on a farm in far eastern Aurora among his 11 brothers and sisters (he was born sixth). He went to Gateway High School while he lived in Aurora. He also attended St. Anthony Catholic High School in San Antonio, Texas from 1970–1972. His father, Bill, was a heavy equipment operator in the construction industry. His mother, Ethel, was a homemaker until the family began to struggle economically and she found work as a bookkeeper when Ritter was a young teenager. At 14 years old, he went to work full time in the construction industry, and joined a local labor union. He continued to work in the construction field, which ended up financing his college education (along with student loans). He enrolled in Colorado State University and completed a bachelors degree, and then pursued a degree at the University of Colorado School of Law in Boulder. By 1981, he had earned a Juris Doctor (J.D.) and was hired as a Deputy District Attorney for the City and County of Denver.

In 1990, Ritter took on a position in the US Attorney's office, and returned to the Deputy DA's office two years later. In 1993, Ritter was appointed as Denver's District Attorney. As DA, he created one of the nation's first drug courts, as well as taking on white collar crime in metropolitan Denver. He worked extensively on the prosecution of sexual abuse and domestic violence, as well as criminals offending senior citizens.